Start off by doing a Leg Roll Over. Once the devilstick has almost finished its roll over, and before it falls off of your leg, jump up with the foot that is still on the ground. Bring this leg up so the devilstick can roll off one leg and continue to roll over this one.
So one complete cycle of this trick would be: From the right handstick roll the devilstick over your right leg. Then jump up to continue the roll over the left leg. The devilstick will then fall off your left leg and the left handstick can hit it.