Baja's website says the kdx rewind is $90. They list their rewound unit @ 70 watts.
For less money (mine was $72) you can get a stator from moose (made by electrex) that is also rated at 70 watts.
No downtime waiting for the part to come back. The moose part comes without harness....so you DO have to solder/crimp a wire.
Take care with removal/replacement of the flywheel. It's much easier to do with air tools. A flywheel removal tool is a necessity. About $12 in any bike shop.
It can be done with hand tools. That way, a flywheel holder is a good thing. You can make one out of a couple bolts and a piece of wood. It'll be self evident with the cover off.
Correct torque on reassy is critical! After the FW is back on, run a small screwdriver or suitable tool through the keyway to make sure your key is indeed IN the crank. It's not tough to have it back out of the crank when you put the FW back on. (how would I know that? ;) )
Use a thread locking agent!
BTW...the listed wattage I know is true for the 'H' model US bikes. Overseas kdxs (with batteries and rectifiers) may not be the same. Don't know how that relates to puerto rico.