I thought this next job was going to be a bit fiddly but actually wasn't as bad as I thought. Like most I expect the wiring gaiter/sleeve between the body and tailgate was worn and splitting.
http://i1230.photobucket.com/albums/...psofrmk37b.jpg
So years ago I bought a pair of new ones but thought I may end having to cut and rejoin the wires to feed them through. Then I got chatting to one of the technicians at work who lent me the tool set below. It still wasn't the easiest of jobs, my patience is pretty low in fairness, but once I had worked out how to remove the spades from the connector it was ok. I think it was tool D I used in the end. I mucked about being all gentle but it turns out a bit of force was needed. There is a small clip on the spade the hooks over a step in the connector and you just need to release it.