I don't know about the 67, but I changed the tail panel on my 69. I had to cut the welds at the quarters, across the bottom where it attaches to the rear valance and to the lip of the trunk floor, and disconnect the trunk latch plate. There were a lot of welds and prying to get it disconnected. Both of my quarters were in bad shape already at the back corners, so I wasn't too concerned with a little damage, and I put in a new rear valance, quarter drops and trunk floor. It still took about six hours of labor. It might be easier for you to cut out the old tail panel leaving enough metal at the quarters to attach to and cutting the welds across the top and bottom. Make sure the trunk channel lines up well. I did my own labor, so I couldn't tell you the cost. Good luck.