You should have seen how fun it was before there were plug and play harnesses. You had to extract wires out off the EU connectors and wrap them in electrical tape.
Good luck on the sale. Once you do the install, it really becomes pretty fast. It took me about 20 minutes to take out the Rev I, put in the Rev II, install the new firmware and map. It probably took me 90 minutes the first time I did it without a PNP harness.