Step 1. Remove the fixing screws located underneath the locomotive. The coupling will become loose. Remove this and place it to one side with the fixing screw.

Step 2. Locate the fixing lugs inside the trains chassis. Using a small flat-head screw driver, pry each lug out of it's socket and gently pull the rear of the chassis down, until the entire chassis is removed from the body. Take your time, the lugs are easily damaged.

Step 3. Locate the three capacitors situated on top of the motor, and connected to the motor contacts. There will be one orange and two red capacitors.

Step 4. Unsolder the red capacitors from the motor contacts.

Step 5. Remove the decoder from the protective packaging, taking care not to handle the PCB directly as static electricity will cause irreparable damage. It is important to protect the decoder by wrapping the PCB with insulating tape. To prepare the decoder, remove the plug and separate the red, black, orange and grey wires. The rest can but cut as short as possible and insulated with a piece of insulating tape. Strip the red, black, orange and grey wires and lightly "tin" them with solder. Tinning the wires will make the installation easier. When soldering care must be taken not to breathe in the fumes.

Step 6. Solder the orange wire from the decoder to the first motor contact.

Step 7. Solder the grey wire from the decoder to the second motor contact.

Step 8. Solder the black wire from the decoder to the first red capacitor.

Step 9. Solder the red wire from the decoder to the second red capacitor.

Step 10. Ensure that none of the new solder joints are touching each other or any metal parts. Place the locomotive onto the programming track and test to make sure that the installation has been successful. Remember that the decoder has a default number of “3” and it is recommended that you code the locomotive to the number you require. Test again.

Step 11. Insulate all solder joints as shown and secure the decoder against the locomotives chassis using BlueTack or an other suitable fixative.

Step 12. Place the locomotive onto the test track and test again. Once you are satisfied that the decoder is functioning correctly, replace the loco body, ensuring that there are no wires caught in any moving parts, or 'pinched' between the chassis and the body. Test once more to ensure that the installation has been totally successful.