I'm sorry I can't help - you just reached the point where I wouldn't go. ;)
I always send my potted motors to Jenny at sew-classic for re-wiring and for the motors that attach to a bracket that attach to the machine, I just buy a new motor. It's already wired, it's clean, strong running - and at only $22, it's cheap. :)
Getting a potted motor refurbished is more than just soldering on some new wires - Jenny cleans everything thoroughly, replaces the brushes if they need it, etc. It's not cheap, but I know that the motor is safe when she does it - that's not something I could be sure of, if I did it. :mrgreen:
Electricity is one of those things I'm extremely wary about - perhaps unnecessarily so, I don't know - we all have our little quirks and maybe this is one of mine. But, there are very few electrical components that I will touch. :)
Good luck and have fun! :)