Barry,
No tutorial that I'm aware of but it is pretty easy. Turn the toneboard section 5/8"-ish to fit in your jig, then turn a male end on it 1/2" diameter at least an inch long. Drill a corresponding hole in the wood that will show on the insert (black ash burl in this case), using a brad point bit to ensure you have a flat bottomed hole. Without a flat bottomed hole you'll end up with a void in your exhaust bore when you drill the exhaust out. I stop mine short of the exhaust end so the sleeved wood doesn't show, but you could run it all the way through. Epoxy or thoroughly glue the two pieces together and let dry. Then grab the 5/8" end in the collet chuck and turn and drill your insert. Takes a little practice but honestly it isn't all that tough. Just a lot of extra steps.