This installation is for a Z Scale American Z Line GP-7 using a TCS AZL4 decoder and was performed by TCS.
American Z Line GP-7 prior to TCS AZL4 decoder install.
First, carefully pull the shell off of the locomotives chassis to expose the factory light board.
With the shell removed, next remove the factory light board from the locomotives chassis. Do this by carefully lifting the rear (right in picture above)
of the factory light board and slide it towards the rear of the locomotive.
With the factory light board removed, next install the TCS AZL4 decoder. Installing the AZL4 is the reverse process of removing the factory light board completed in the previous step.
You have now installed a TCS AZL4 decoder into your Z-Scale American Z Line GP-7.