With ours I was able to buy a new motor from the manufacturer's parts
supplier fairly reasonably, and it was just a case of a couple of bolts
holding it in place once I'd got the lid off the machine. I wouldn't play
about with anything associated with the microwave zapper or whatever, but
it was pretty simply and innocuous to repair the motor in mine.

Definitely stay away from the microwave side - the capacitor in use there
holds lethal amounts of volts and amps, something like 2KV at 500mA which
*will* kill you. First rule of working on a microwave is to *always*
discharge that cap, even if you're not going to be working near there cos
it's so easy for a finger to stray, or for you to drop a screwdriver or
whatever.....

Hellraiser.............