Day 1
This is just a tutorial. Also, let all your Pikmin grow flowers before you pluck them, but this does take up alot of your time.
Day2
Ok, so now you have 25 Red Pikmin total and by the end of the day you should have a little over 100. Right outside of the circle you start in are Pellet Posies and Bulborbs to grow your population. The easy way to kill the small Bulborb (or Dwarf Bulborb) is by having a Pikmin crush him by throwing a Pikmin on his back. Then take about 30 Pikmin and get behind the Large Bulborb (or Spotty bulborb) and throw the Pikmin on the its back repeatedly. You will then be able to get the part. Have your Pikmin bring it back to Olimar's ship. Behind the Bulborb is a bone gate like the one at the entrance to your base. Break it down and kill the Bulborbs in the area. You will also find the Yellow Onion there. Leave both the Bulborbs. By now you should have 100 Red Pikmin, put the them away. Now you should go and get the Yellow Pikmin get all the seeds and Bulborbs in the area. (Optional)For the final part of the day carefully blow up the stone walls with bomb rocks. (the ones by the Yellow Onion)
Day3
'The first thing you should do is call out all your Yellow Pikmin and about 40 Reds. Get the Pellet Posies right outside of your base. You'll notice a ledge where a red pellet was lying but now you must throw all of your Pikmin up there and then walk through the little puddle come around and get them. Kill the Spotty Bulborb guarding the ship part''' and bring everything both back to base. Now find the Bomb Rock that are in the can by the water and tell your Yellows to pick them up. Then go to the stone wall by your base. Blow it up. The get your Reds and kill all the Bulborbs. Then break down the brown wall, kill the Bulborbs and get the ship part. If you have enough time go to the wall by the spot that you first found the Yellow Onion. Get the Bomb Rocks in that can and blow up the wall on the RIGHT. Defeat the Bulborbs, get the ship part on the ledge and blast off. (You can get the ship part from behind the black wall by using 9 Bomb Rocks.)
Day4
Okay now you're in The Forest Navel and the first thing you should do is find out where the Blue Pikmin are and go and get them. Only kill the two flowers in the water and get the 5 pellet. Once you have picked all these Pikmin kill the three flowers and wait until the Breadbug tries to steal them. When the monster does so have your Pikmin play tug-o'-war with him. Just so you know you have to have two Pikmin on a pellet to beat him. Once you kill him a ship part will come out. Before you take it home go straight and fight the beetle monsters that come out of the ground and then start taking the ship part home. Once you have done so near the Blue Onion you might have noticed a big gear on a cliff. Go to the pile of sticks on the cliff next to the gear and have your Pikmin build a pole that they will climb across and get the ship part. As your Blue Pikmin are taking the gear to your ship go and get 50 Reds and have them break down a bone gate next to your base. Put them away and have the Pikmin who were carrying the gear go down the path where the gate was and get the ship part down there. By the the end of this day you should have over 100 Reds about 50 Yellow Pikmin and about 45 Blues.
Day5
For day 5 you should go back to The Forest Navel. Take out 60 Red 40 Blue. Take all of the Reds only and head towards the bridge making spot near the Blue Onion. There are two bridges there so make them both then kill a few Blowhogs on your way to the mushroom monster to the left of the bridges. There should be blue mushrooms all around you and also a giant mushroom monster. Have your Pikmin attach its legs until the mushroom flips over when this happens throw your Pikmin still at his legs. If the mushroom monster has a chance to get up again quickly call your Pikmin and if you don't they will become Mushroom Pikmin and attack you. Once you kill this monster have your Pikmin grab everything. On there way out there will be monsters that you have to distact if you haven't already killed. DON'T LET THE RED PIKMIN GET THE BOSS SPOILS. You must save them for the Blue Pikmin so drop them in a safe area. Go to the Red Pikmins' Onion and put them away. If you have more get the remaining Blue Pikmin and gather some of the monsters you previously killed. Go to your radar and you'll see a huge body of water. Right next to it you'll find another ship part right below where the mushroom was. Take your Blue Pikmin there and walk through the water and come around to the the other side and leave 30 of your Pikmin to work on the ramps you should still have another 40 or 50 so take them into the water and kill one of the frogs have your Pikmin get the ship part. Distact the other frog to save time. Once those Pikmin are safe go make sure the other Pikmin are working on the second bridge. Once they are done with that have them get the ship part and end the day.
Day6
This will probably be the hardest level to fit in especially if you didn't pick your Yellows from before. Go to The Forest of Hope and call out all your Blue Pikmin and head through the broken bone gate. Go to the top right hand corner of the lake and through your Pikmin up there. You also might want to put a few on the other bridge if bugs have eaten it. Once you get that ship part being brought home quickly go throw the stone entrance of your base and turn at the dark bone wall where you will see a wall still standing. Have your Pikmin start breaking that one and then go get the rest of your Pikmin to help. When you break that wall go to the next wall which should be darkly colored. Behind the second wall is a giant beetle monster he will turn towards your Pikmin and his head starts glowing and he shoots giant rocks at you. Run to one side of him and turn towards him when hes about to be facing you start throwing Pikmin at his forehead until hes about to attack when a Pikmin hits him. The back of his body will then open up so take your Pikmin and throw them on his back. Once you have killed this monster take him and the ship part back to your base you should still have half of the day left. Also when fighting the next boss don't worry if you lose 30 Pikmin because on Day seven you will have plenty of time to grow more Pikmin. Go to where the Yellow Pikmin started and go through the stone wall on the left lead your Pikmin into the small puddle and throw them on the side of the box you cant reach. They will push the box out of the way so you can proceed. Go to the left wall with your Pikmin and go to the ledge as you may have noticed there are giant birds coming out of the ground. To kill the bird you have to have your Pikmin swarm the bird when his beak is sticking out of the ground only. You might have to do this twice to kill him but as soon as you do have your Blue Pikmin get the ship part. Don't worry, they should just jump into the lake and not go past the other birds.
Day7
Today you must go back to The Impact Site. Take out a few Yellows to use bomb rocks and all the Blue Pikmin you can. First of all look inside the box you pushed on Day 1, and there should be bombs for your Yellows. Go on the big stump and blow up the wall. Thats all you need your Yellows so get your blues and look for an oyster that has a ship part rather than a pearl. To get the ship part throw your Pikmin into the oyster and have them attack it. Don't leave your Pikmin in there too long, otherwise the oyster will eat them. For the rest of the day once you get the ship part you can grow all the Pikmin you'll need for the rest of the game probably.