I made sure it was perfectly square to the spar and clamped it and the spacer stock into place. The other 7 holes were back drilled through the holes in the spar.
Then I bolted on a nutplate to use as a guide and then match drilled the holes for the nutplate rivets. I removed the bolts and the spacers and then countersunk the spacers for flush rivets. Then I cut the spacer length to the right size and then cut in a 1" lightening hole as per the plans.
I cleaned and primed everything and then bolted it along with the bellcrank brackets to the spar. I made one mistake. I sued the wrong sized nutplates on the top side of the tie down bracket. I had to drill them out and install the right ones.
I started drilling the skins.