If this is your plan, then I would suggest you NOT get the factory style plastic sockets, and I highly recommend the all-metal ones like shown in the photos above that Bjorn and 68blackbird used. Then all you'd need to do is attach a ground wire to the metal, and it saves you the hassle of having to cut away plastic to expose the metal. Just use a small ring terminal and a sheetmetal screw and attach a ground wire to each metal socket. That would be easier and more secure than what I did. The only reason I did what I did was because I had already purchased a complete new replacement rear wire harness, and I thought I'd go ahead and use it. But starting the project with metal sockets would have made it easier for sure.