Clamped the roll bar in place and climbed into cockpit to back drill through the spacers. Used an angle drill to get a good mark for location of first hole. Got out and removed roll bar, then drilled the mark to #40. Reinstalled the roll bar with clamps and a cleco in the first hole. Repeat process for the other three holes, one at a time. Once all were drilled to #40, dis assembled and began upsizing all the holes on the bench to proper size per plans. Deburred all holes and reassembled the roll bar on the fuselage. Put the bolts in from the bottom as this was easier to capture the spacers. Will still have to remove the roll bar in the future and will install bolts correctly on final assembly.