That's a lot harder. Move forward, medium speed. Pull an endo, back wheel comes off the ground. As the back wheel comes down, use the momentum and bring the front wheel up. Pull enough so you feel like you will fall off the back. Instead of stepping off though, jump up using your feet to pull the back wheel up and place it under you to keep your balance centred. Repeat. As you gradually get better, try to stop moving back. Then let the front wheel drop more then usual and add a kick with your good foot, whilst letting go off the brake and jumping up and forwards. Pull the brake before you land and repeat. Easy