When doing ur kick into the windmill, u have to swing it around, then **REALLY HARD* diagnolly up. All you need is that one kick (several if doing continuous) to get a good start on windmillz. Also you have to be extremely quick when turnin to ur front side. If u swung ur first kick hard enough u would get sum air and then u could easily kick ur right leg underneath.
well, hope i helped,,Peace

Practice, practice, practice!!!
