Plenty of technique videos out there so I won't go into techniques.
Practice the footswap on land first before going out (even better if you have a skateboard to use)
I found it easiest to learn when nicely powered as you can sheet in to support your weight for balance. Having the kite a little higher makes it easier to learn as you won't get pulled over the nose as much.
Many find the foot swap after the gybe easiest to learn. Try moving your front foot inwards on the board a little before the gybe as this will help keep the toeside pressure which in turn keeps the board more stable when you move your back foot.
Kite choice can make a difference. I went from 1 in 4 to 2 in 3 success rate during a session where I borrowed a proper surf kite (as opposed to regular freeride kite). The additional drift and softer power delivery allowed me to forget about what the kite was doing and concentrate on the board and my feet.
Takes a bit of perseverance. Find a quiet spot and then go for it at the beginning of your session before you get tired. With shallow flat water you'd probably crack it in 30 minutes. Longer if you have to drag to recover your board. It really is something you can make big leaps in an afternoon if you commit.
If all else fails. Get a sliding harness