This is a very straight forward installation to start with. Any single function decoder will do, as only the motor functions will be required. Ensure your decoder can handle at least 1amp.

For this installation I used an old ZTC 211 decoder as I had 20 or so hanging around. This is a single function decoder. The harness has only four wires being Red, Black, Orange, Grey. As always the red and black wires go to the pickups,
The grey and orange wires go to the motor terminals.

Remove the body, and tender from the loco. Snip off the pickup wires,
And discard the capacitor.
Cut the rear weight to make room for the decoder.

I shortened the Harness wires as space in the tender is limited. Note the shrink tube fitted over the red and black wires to cover the cable joins. This is pulled over the joint and shrunk in place with a lighter or other heat source. The decoder can be held in place with Blue Tack, or double sided tape. A tab of black bath sealer is also useful for holding decoders in position,
and covering/holding wires.

The last picture illustrates the excellent pulling power of the 2P/4F combination