Lift the door up and pull the bottom of the door out of the track. Have a friend hold the back of the door to prevent it from falling once it is lifted out the track. Set the door down. Remove the plugs from the roller adjustment screws if the door does not lift out. Tighten the screws to retract the rollers, then lift the door out the track.
Vacuum out the inside of the track to remove mud, dirt and debris.
Pop the rollers out from the bottom of the door using a flat-head screwdriver. Clean away any dirt from the rollers with a rag and vacuum cleaner.
Lubricate the rollers with silicon spray lubricant.
Wipe the door frame to remove dirt. Pop the rollers back on and reinstall the door by lifting the head of the door into the top track, then setting the rollers in the bottom track.