When pulling hard it bends, permitting the coupler to lift out of its mate. With a single engine, this is not a problem, but when ran at the module club MU'ed together, it failed repeatedly. Problem repaired with tin can stock. The body pulls straight up with a little wiggling. No need to remove couplers as the walkways, pilots and couplers remain.
Decoder stays with the motor, just unsolder the light wires to remove.
Removed small amount of weight, sawing off the small extensions that project to the cab center to reduce the risk of electrical shorts. Scrapped the grey plastic lamp and buss board over the motor, and cut the mounting lugs off. The plastic light guides had to go also. Mill the lumps off of the ceiling where the decoder needs clearance. The decoder is mounted solder side up with carpet tape separating the motor and components.