I believe what your Hobby Shop was telling you was that you need to take off the jumper plug that's attached to the 9pin harness. The white part will separate from the gray jumper. If you pull it off, you'll expose the 9pin plug that you can hook up your TCS T1 decoder to. You do not need to, nor should you, remove the 8 pin plug (the pin with the holes in it) for successful DCC operation.
