You need to be able to do 50-50s and to drop in the mini ramp you are trying this on.

Drop in to get the speed. Now as you start comming close to the coping start to do a F/S kickturn and make your back truck get on the coping. As soon as your back truck gets on stick the front truck on quickly. When you get into the position you might grind instead of a stall. That is ok, but you might wan't to do a quicker kickturn and try to not go at very much of an angle. Just ride straight up the ramp and lock them trucks on. You should be able to get into this trick in just a few trys. Comming out is the hard part of this trick. You have to lift the front truck up a little and pivot until you are feel the back truck comming off then just put your nose down and roll away. You should learn this trick in under 30 minutes if you just keep trying it one after another.