Finished separating the center section and tail section and set up for beginning mounting of strobe power pack, elevator servo, etc. Located mounting bracket for strobe purchased from Van's. Determined hole locations on the top flange to the stringer and drilled. Drilled bottom holes to match. Removed and deburred. Riveted in K1000-8 nutplates onto bracket as directed. Riveted in bracket. Made the mistake of riveting the top first and then couldn't reach the bottoms. Drilled out top rivets. Riveted in lower rivets and then tops. Temp mounted strobe power pack.