Sunroof repair entails removing the sun glass, cleaning the drain tubes, checking for wear in the seal and testing for any faults previously occurring. It also involves replacement of already worn-out parts, removal of the sunroof and its re-installation.
Unscrew the sunroof for inspection using a hex socket by tilting it to the "vent" position. Look for any strapped or stripped gears. Clean the trough by blowing air just below the rubber seal, wipe it with a cloth and remove any debris that may be blocking the sun-glass from closing easily. Once you locate the sunroof drain tubes at the corners under the seal, you may blast compressed air into the tubes to remove any dirt. Try cycling the roof with the car on to determine if the problem is solved.
Slather the gears with lithium or marine grease for better future operation. If the problem persists, it may involve replacement of the sunroof. Take off the interior trim around the door pillars and any overhead handles. Pull the headliner down. Disconnect the wiring and unbolt the whole system.
Do a function test before putting the interior together to ensure a perfect alignment. Ensure proper bolting of the sunroof to avoid any future leaks.