Go buy a cheap ass motor from a junkyard, I had to fix that same thing before and it was like $20 total to fix myself, but if you go manual, that's just retarded, that's a lot of work and there's no real reason to do it unless your whole door is just ****ed and nothing can operate unless you replace the door, then you could just convert, but if your door is that ****ed in the first place, then you probably won't even be able to make the manual dooors work either.