Firstly cut/grind a V type cut into the caliper grip edge as below, the front one bigger than at the rear
Use a piece of plywood to create a base for screwing down the full wingset
Screw in down to keep it from moving and place on a flat surface
Cut out some shim shapes from a thin plastic lid, these are cut from a small butter tub lid with the hole made by heating up a screwdriver end and melting the hole as you can see
Place the wixey on the caliper as shown the wixey base has strong magnets to hold it still, then using the V cuts place the front wing edges between the caliper legs, close the V cuts in tight, lock off, and zero the wixey
Move the caliper over to the rear wing and measure the factory set angle, in this case 1.3deg
Place one shim under the rear screw and note the information for one shim
Then record the difference for two shims,, get to the water and try only one shim first.
for me 2 shims was not a great feeling, one worked better than none, but we are looking at very small thin shims here so don't go mad and try thick shims as the difference can make your riding experience a nightmare, start super thin,
And remember what works for one rider might not work for someone else,
on Steve's (Sfolis above) set up, on his shimmed 720, I could not ride it, awfull for me, not too bad for Steve.I had to jump off out in the bay and swap back to my board and Steve sailed around quite happy on his.