HI, I thought I'd mention my ordeal with removing the rear wheel to put on my freewheel. The reason I'm posting this is because at some point, someone is going to have a flat tire on the rear wheel, and will have to do this. If it happens on the road, you might be screwed.
Normally when I remove a wheel, I turn the bike upside down and balance it on the seat and handlebars like a tripod. The XP is so rear heavy, that it pretty much balances on the seat and wants to rock backwards. I had to put something heavy on the handlebars to keep it in place. even then, whenever I tried to exert any force on something (like break a nut loose) it wanted to rock back. this is a drag because that's the position I use to do any chain, brake, derailleur maintenance. I'm looking at getting a heavy duty PARK repair stand, but that's another $200.
That aside, unplugging the motor and removing the nuts was pretty straight forward. But when I went to lift the wheel out, OMG it was stuck like glue. After much pulling, I managed to pry it up with an unconventional use of a tool. I changed the freewheel, and went to reinstall the wheel. So here's the problem, the spacing of the dropouts is too tight. In other word, I would have to spread apart the rear ??? (I don't know the word to use, on a normal bike I'd say the rear triangles) the parts with the slots that the wheel fit into. It would help if I had another person who could spread apart those things while I dropped the wheel in. by myself it was a chore. but i got it done. It was easier with the rear brake caliper removed so I didn't have to also worry about aligning the brake disc at the same time.
After I was done, I kicked myself because I have a tool that would've probably helped. It's one of those little wood clamps, with a trigger, you use when gluing part together. The end of the clamp reverses, and then it's a spreader clamp. with the wheel resting almost in place, I could've put the clamp through the spokes and spread the dropouts.
Anyway, I hope this makes sense, sorry I didn't take pictures but I was in a big fat hurry.