Hey Dean,
Light wind longboard gybes can be tricky and the Exocet is a bastard given it's very narrow but thick tail. Anyway....
Centreboard up - not impossible to gybe with it down but makes it much much harder
Weight back - ideally your trying to pivot the board around the tail, sounds obvious but if the board is flat it won't want to turn
Be aggressive with your feet pressure - particuarly the outside rail, trying to push the rail around, pulling in on the inside foot doesn't hurt either
Try and draw the rig over the board and to 'leeward' - basically trying to get the balance of the sail over or past the outside rail
Don't be in a rush to flip the rig, you really want the board to flatten back out and your feet set and planted before flipping, even try sailing out on a broad reach clew first while practising, then flip
Then do it all in not a lot of wind and in swell - easy!