If you look closely you can see the four holes that were pre-drilled before the assembly process started. The arrow points in the general direction. The front spar and the forward rib are not yet drilled.
The instructions say to use an angle drill. I could not get the angle drill to face straight into the part.
My solution was to remove the rear spar for additional room and to use a long drill. I used a glove and held my right hand against the bit to get it straight into the part.
Looking from the back side.
The front side. The black tips of the clecos are visible.
The set-up on the HS is complete.