2002 Cavalier Sunroof Motor

So, I get a call from my brother. He is having a problem with the power sunroof in his 2002 Cavalier (OEM installation). Says that it is not opening all the way, and sounds like the motor is giving out. If he lets it be for a little while, it goes a little more, but progresses less and less. Definitely sounds like the motor to me also.

Anyways, takes it to the garage (a Buick/Pontiac/GMC dealer) that he gets all his vehicles serviced at. They won't touch the thing, saying sunroofs are too involved. Gave him the name of a place about 25 miles away. Calls the other place, and they won't even give him the price on a worst-case scenario. Now I know they should look at it first before estimating, but being that we don't even know where the place is, we don't want to get taken by a shady operation.

So, before taking it in, he wants to take a look at the motor himself. Where is it located (Headliner?), and what would a replacement motor cost? He wants to get an idea if this is something that could be done on his own, as he already did a power window motor. Any pictures/diagrams would also be appreciated. Thanks in advance.