Apache Blackhak installation was pretty simple. I passed the shaft through a pre-existing 1-1/8" hole that formerly housed a button. On the bottom of the control panel, I used 4 wood screws to attach it to the underside of my control panel.
Because the shaft is much smaller than the 1-1/8" former button hole, I drilled a hole in a black plastic button plug to accept the shaft, & then installed that button plug--that makes the installatoin slicker.
Were I doing this installatoin over from scratch, not using a pre-existing hole, I would drill a hole that's barely big enough to accept the shft, with some interference to hold the unit snug, install the 4 screws underneath. Then, I'd remove the unit, take the next bigger drill bit to open up the shaft pass-through hole just a tad, then re-install. That way, I'd have a the shaft perfectly centered in a hole only just a bit bigger than the shaft.
-Jason