Step 1: Go to the Math Room.
Sorry for not having a picture.
In the Barnett Collage hallway there is a room with a sign that reads '1 2 3'. Go in there and walk up to the chalk board. you will be able to enter cheats.
Enter the following codes.
Step 2: Activate the Codes.
Load a level normally, then press what ever button brings up the pause menu (The escape key on a pc) and select 'extras' . then use your movement keys to choose the extras you want enabled. press whatever button enters stuff for you console to turn it on.
run around and collect bricks. earn money