Completed fitting of left wing landing light assembly. Marked right wing leading edge with template and cut out leading edge for landing light opening. Filed and cleaned up opening. Measured and drilled for landing light attach brackets. Riveted landing light brackets. Drilled out front spars attach fittings. Drilled hole thru leading edge to rear face of spar with 1/4" bit, then drilled up-size to 23/64"; then reamed with .374 (.001) undersize reamer. 3/8" mounting bolt fit perfectly. Cleaned up holes and temp installed 3/8" mounting bolt and hardware.