What was found
LANDING GEAR DOOR OPEN LIGHT REMAINED ON AFTER GEAR EXTENSION. CREW RECYCLED GEAR WITH SAME RESULTS. EMERGENCY WAS DECLARED AND ALTERNATE GEAR EXTENSION PROCEDURES WERE UTILIZED. AIRCRAFT LANDED WITHOUT INCIDENT. MAINTENANCE REPAIRED LOOSE FASTENERS ON RIGHT GEAR DOOR ROLLER ASSEMBLY. ALSO, INSTALLED NEW SKID PLATE ON GEAR DOOR DUE TO DAMAGE INCURRED ON LANDING. OPERATIONAL CHECK NORMAL. AIRCRAFT RETURNED TO SERVICE.