Reviewed compliance procedures for RV-8 Service Bulletin 16-12-16 regarding missing center section bolts. Gathered bolts, nuts and washers and nserted bolts from the front. Discovered it would be very difficult to locate washers and nuts on bolts due to tight spar box access, so used magnetic stick and flashlight to locate bolts in holes from the inside out to front. Supported back of bolts with length of wood trim and placed washers and nuts onto bolts, finger-tight.