Paul I got one from wemoto too just few days ago (Electrex)
Did not install it yet, but connection is very easy. Just remove old rectifier unit and regulator, connect new regulator into big connector from alternator and 2 more wires as in instruction sheet attached in package.
The "biggest problem" is to decide how to fix it into bike, case is hestsink, so will be hot during operation - take into consideration. Positions of holes does not fit old unit holes.
I tried to find good place in my K7 750, will need to fabricate some metallic plate-adaptor. Did not study yet on 550.