My passenger window only goes down a couple of inches and needs to be helped going up. I am thinking that replacing the motor would solve this. I've heard good and bad stories about doing it. Is it really that bad, or difficult?

 

yes that sounds like your power window motor is getting worn out. However it is possible that a good cleaning and greasing of the tracks will solve your problem, or at least buy you time on the life of your power window motor. Sometimes over time the factory lube becomes more like sticky dirt.

Its not too bad of a job to change it, Just pop off your interior door panel, then the dust cover underneath of it. you will see the motor through an access hole on the inside of the door, Its self explanatory after that.

 

As Jay said, New motor will fix it. I cleaned and greased mine when I was in there as well. Hardest part in my opinion was drilling out the rivets. New motor came with all hardware to install.

 

May want to also check the voltage @ the power window. Its possible you have so much resistance in the line the voltage @ the window motor is crap.

its really common to have voltage drop on these cars. Stuff that wouldn't be tolerated today.