Here's how to get the slider rolling again: Remove the side casing where the pocket door is recessed, using a utility knife to cleanly cut the paint line and a flat pry bar to gently pull the trim away from the wall. Then take off the doorjamb on the same side and the top as well. Pull the door out, tilting it to guide the rollers out of the track. Clean the track and rollers with your vacuum's long crevice tool, then spray them with an aerosol lubricating oil, such as SlipIt (about $10 for 12 ounces; amazon.com
), on the wheels and the track. Tighten the track in the doorway. Replace the door, positioning the rollers back on track, and slide the door in and out before reinstalling the jamb and casing.