check out the videos made by gunner on you tube
he also does vids of normal tacking and roll tacking:
As you are going into the gybe raise your kite to 11, as you start to turn
bring your back foot out of the back strap and put it in the opposite front strap at the same time you need to downloop your kite.old front foot should be towards the back of the board. its crucial you have the new front foot in the strap so you can control the speed of the downloop. ride away then un-twist your lines.
Without downlooping the kite, a gybe is very difficult