1989 Jeep Cherokee Power Drivers Seat Won't Work

we are looking at a 1989 Jeep Cherokee for my son. The owner says the power driver seat does not work, not sure if its a fuse or what. I suspect the motor is burnt out considering the age. Does anyone know how much this might cost to fix? Or is there some kind of manual override that would allow a person to adjust it without too much trouble? Thanks for any help.