Before starting to fix your kite, your kite must be cleaned and especially without sand or salt.
1 - Open the extremity of the strut, remove the scratch and take out the bladder.
2 - Attach a line on the valve, to return easily the bladder to the same place at the end of the repair.
3 - Push the valve into the strut, then pull the line at the extremity. You kite bladder will be outside of the strut/leading edge.
4 - Inflate your bladder gently. You can then put it under water to spot the hole, or the leaking valve. Use a permanent marker to spot the place to fix.
Then you need to dry your kite bladder, and clean the hole with a non alcoholic pad.
5 - You can stick patches inside and outside of the hole and add glue if necessary.
6 - Put back the strut inside the leading edge, the most flat as possible to avoid twists.
7 - Inflate gently your kite to check if the repair works, then close the scratch at the extremity of the strut or leading edge.