Forget the msource kit, it is useless....the problem is the old grease in the tracks and motor....it turns rock hard and sticky. The only way to fix this is to remove the cable, then remove the motor and degrease it all....then regrease it. The motor, cable and tube are easy to degrease....the tracks not so easy with the sun roof in place. Its the only way to truly get the sun roof working 100%.
Heres a good diy link...
PeachPartsWiki: Sunroof Repair
This is the grease I like to use for everything in the car
AGSŪ White Lithium Grease (WL-1H) - Automotive Grease & Lubrication - Ace Hardware