the heater comes out by unbolting the 4 [5-6?] studs that go thru the firewall on the engine side and removing the heater hoses - prolly easier if the control cables are disconnected first, and the levers are pretty straight forward once you have the control out
I'm finished up my busy season now, and have been intending to work up some detailed info on the TF heaters, seein I've got a couple of each

I'll pull out the delux one I restored last year and take some pics tomorrow
Bill