ERR makes a kit to install TMCC functions. You can find the various types of command kits at 3rd Rail Division of Sunset Models. They are advertisers on the forum. I believe Gunrunner John also sells them and does installations. John is on the forum. The installation is pretty easy. It is a matter of removing the old wiring and connecting the board. The directions are pretty straight forward. You will also need a controller: cab 1, cab1L, or cab 2
Marty