Finish the game and save Chris or Jill you will get the secret key. Then when you finish the game save it and then load the saved game next time and you will start with the seceret key which gives you the other clothes for the person you finshed the game with last. All you have to do next is find the locked door its in the house.
If you finish the game in less 3 hours, when you start again you get a big rocket launcher (unlimitted ammo) you destroy all monsters in one shoot.
Start the game with Jill. When to go off into the dining room, walk back to the main hallway. Wesker will say "go investigate that shot." Go back to the dining room and Barry will say "where did you go?" Walk by the Grandfather clock and a zombie will appear. Barry will shoot him and curse at him. Go visit Kenneth (the place where you met the first zombie) and he will have no legs or clips. The game is to "be easier".
There are 2 rooms with numeric keypads. One of them is the room that contains the bottles and the chemicals to make V-Jolt. The code to enter the room is 345. You will find the 4 bottles to make V-Jolt on the 2 shelves in the room. There is also some writing on the wall inside the room, make sure you read it.
To enter the weapon screen anytime in game quickly press R1, R1, R2, R2, Left, Left and x, x. Remember do this really quickly and you will have a zombies head and a rocket launcher.