can you explain how to drift without brakes? Do you just push the back end sideays or something?

Pretty well you have to get your speed right before you hit the corner.
Most people try to adjust speed using their brakes in a corner, however, when you want to just destroy a berm (such as this), i found getting on the brakes a little bit sooner helps.

When your about to enter the berm start cutting it as if you were going to aim for the highest point of entry, then twist your torso so your back tire is forced into the berm, which in turn will set you back, and slightly push your front end out.

This should produce a nice berm blast!