How to Convert an MMI K-27 to DCC

Un-clip the locomotive component of your train from the track. Turn the locomotive on its right side and un-clip the forked end of the long rod extending from the cab. Turn the locomotive upside down and place it on a foam support, which will secure the locomotive as you remove the rest of its body.

Remove the two screws using a small screwdriver under the rear of the locomotive's cab and the train's trailing truck, then remove the trailing truck. If your locomotive is not already connected to a trailing truck, you can skip this step.

Remove two more small screws, one on either side of the locomotive's equalizer beam. After this, remove the equalizer beam from the locomotive and remove the larger screw, now revealed underneath the beam.

Pull the locomotive's cylinders apart and lift the body of the locomotive as though there are hinges at the back of the cab. Disconnect the two lighting wires from the innards of the locomotive. Mark one side of each lighting connector, as this will prevent you from connecting the wires backwards when you reattach the body.

Unplug the JST 9-pin wire from your DCC component. Unplug the JST wire from your locomotive's PCB unit and connect it to the DCC component. Place the DCC component in the locomotive by attaching it to the engine with tape.

Reattach the body to the locomotive by following Steps One through Four in reverse.