How To Manual?
crouch, then quickly shift your weight backwards, keep your arms straight though
faster is easier to balance
use your legs to push the bike underneath your ass.
I've been trying to do manuals and bunnyhops for a few days i've found that to begin with you might want to try going over a kerb just to get the front wheel of the ground i've found that this works to start with, however don't get to excited and pull to hard as i did that got around ten metres and proceded to fall on my ass :)