I finally got to install the Micro-Train couplers (model # 1015 - body mount) on this engine and it is pretty straight forward. I suggest purchasing the preassembled couplers to facilitate installation and minimize the aggravation factor.
First, remove the engine’s shell from the chassis. There are a pair of metal nubs that are centered on the chassis that hold the plastic body shell on. Carefully spread the shell apart and the chassis can be worked off.
Next, remove the dummy coupler screws and remove the couplers. There is a plastic post that will be exposed once the dummy coupler assembly is removed. Cut this post off flush with the body. There will be a small hole left behind that will be used to act as a pilot hole for the Micro-Trains coupler mounting screw.
The inside edges of the shell’s coupler pocket will have to be filed a bit wider (approx 1/32" wide on each side) to accommodate the Micro-Trains coupler. Once it fits, secure it by using the mounting screw provided but cut about 1/64" from the mounting screw first so it doesn’t punch through the nose platform when you screw it in.
The couplers tend to stick out farther from the locomotive’s body more than one may like but because the clearance between the rear of the coupler and the trucks is EXTREMELY close you don’t have much choice.