Those instructions are are a lot of help if you don't have have them.
They're about the best illustrations of the installation I could find.
The holes for the threaded studs on the brackets are already in the channel like the instructions say, the whole units sits off-center to the passenger's side and they're the only two it will line up with. Just locate it in those holes and mark the front holes for drilling, the template is excellent for reference but it makes no sense to try and measure it if you have the case. I set everything up with the player out of the case. A lot of them are broken installing or removing the units and just handling it when they're out. The plastic they used is brittle as glass and the units are bigger and heavier than they look. The cases also get broken because the rear brace is missing, one good bounce or somebody kicking it and it can crack it across the front where it screws to the unit and on the sides, a lot of weight pivoting off those hangers.
I've been working on installing mine and the brace was missing so I made one last night. It just has a couple of simple angled bends that take hours to figure out.
I can take pics of anything you need to see, wiring is pretty straight forward so that should be no problem unless the plugs are cut off. They're are only two small holes needed for the sheet metal screws in the front brace tabs, one for the brace into the heater case if you don't have A/C.