KennyB-
I haven't worked on a backshop before, but it appears both the upper and lower roof sections are designed to lift off for easy access to the shop floor and the controls/motherboard. Once the upper roof is removed, the motherboard can be easily serviced. Like other TMCC locomotives it appears the board is held in place with 4 washer head screws; the electrical connections are all modular leoco-type plugs which release with a gentle pull on the connector.
Hope this helps!
-John