I haven't installed a TOM, but read on a thread a long time ago that Warmoth drills a grounding route to the hole closest to the control cavity; if you pay the $10 charge they install the grounding wire.
I've installed a number of Wilkinson studs, and you can use the same technique as ferrules; strip the end of your ground wire and run into the hole then insert the stud and start pounding it in with a small hammer carefully; once it's started/true cover with a folded washcloth and carefully hammer the rest of the way in, checking frequently and being careful not to go to far and hammer body wood.