Sunroof Grinding Noise
 

For awhile now I have not used my sunroof/moonroof. The reason is, I noticed that it would open to the vent position, and then when I lower it, it would not lower. I could lower it by hand to get it closed (just pushing it down from outside). While trying to lower it with the power, I would hear some grinding (kind of like the cable grinding on the window regulators that go bad). I also hear this grinding when trying to open the sunroof. From that point on I have just kept it closed and not used it. Well, recently I had to remove the headliner to repair a leak near the sunroof and thought, "I should attempt to get the sunroof working."

I am now ready to do this, but I don't really have a lot of time, meaning, I'm assuming, I need to drop the entire sunroof, inspect the cables/motor and determine what needs to be done. With that I have a couple of questions:

1. Is it worth trying to repair (although I'm not sure the issue, but I believe the cable ends might have worn out)?
2. Are there any parts that can be obtained for any fixes in advance?

That is all for now, any help is appreciated.