Go to pro freestyle (if not unlocked enter "IGIVEUP" as a cheat) put it on freeride and go to "Pro's Backyard" then go to the 4 sided jump next to the ramada and go up that hill until it turns to sand then turn around and hit that jump, pull back, let off the gas for a fraction of a second then hit the gas while pulling back in the air. And if this doesn't work I don't know what will.