I have not done one on an AV. ?But I did replace the over lay on my 2000 Silverado when I had it. ?I removed the over lay and then put the new one on. ?It was more difficult than I thought. ?I do not want to scare you from doing it, but my kit I got, did not come with the needle removing tool. ?When I got them off, and swapped out the overlays, and reinstalled the needles, for some reason, my temp guage needle started to move for me. ?So, I was never sure if the needles were accurate. ?If I would decide to do it to my AV, I would probably go with the whole guage swap that I believe the guy is Prime Power sells. ?He sells the whole speedo cluster and he can customize the speedo with overlays and needles from any GM vehicle. ?He has a 12 month 12,000 mile warranty I believe. ?Also, he guarantees the speedo cluster to be accurate.
I've done what you're asking about. If you pull off the stock overlay there is only clear plastic behind it. When I put my new overlay on, I could see all the junk back there...PLUS you couldn't tell what service lights were lighting up. A space may light up, but the text was on the old overlay and the new one didn't have the text on it so just a little space would light up.
I ended up cutting out the old warning light area and cutting up a green tinted $.59 folder and using it behind the overlay. I think it looks pretty good but it was more of a job than just popping one off and putting another on. The needle removal and install is also a little nerve racking.