Select "Options" in the in-game menu, then "Cheats", then "Retail Cheat". These codes are case-sensitive.

Effect	Password
Auto Fader	I Hate Crossfading
Auto Scratch	Soothing
Auto Tapper	Look No Hands!
Invisible DJ	Now You See Me...
Unlock David Guetta	Guetta Blaster
Unlock Tiesto	In Trance We Trust
Unlock deadmau5	Open The Trap
Unlocks all content (Disables leaderboards)	VIP Pass