This installation of the TCS L1D4 Decoder is for N-Scale Life Like GP20 and was performed by TCS
First remove the shell by gripping it in the middle and lifting up.
Next, slide the lighting board towards the rear of the locomotive and lift it up as shown in the image below.
Reverse the the movements used to remove the lighting board to install the L1D4 decoder. NOTE: care should be taken to ensure the motor tabs on either side of the locomotive are overlapped by the motor pickup tabs on the decoder.
With the decoder installed and the motor tabs properly contacting the decoders motor pickup tabs you are ready to replace the shell and run your engine.