I will be updating arc flash labels on numerous working locations which means the old label has to be removed and a new one applied. By design these labels are very rugged and difficult to peel off. Anyone have experience with tools or techniques that make the old label removal more time efficient?

I'm not a huge fan of sticking new labels on old labels unless it's unavoidable, I think it looks sloppy unless the two labels were perfectly lined up.

I never remove labels; they are too hard to remove. I just line it up as best I can and cover the old one with a new one.

+1

What I hate is when the old one is crooked.

I have gotten away from insisting the AF label must be of the most permanent construction available. I seem to regularly find cheap paper shipping instructions labels still on 40 yr old gear.

Heat gun. But be careful. Too much and you strip the paint. Just enough to soften the glue and peel it up. Once removed you can either stick the old label back down or use a little solvent to clean up the residue first. Again too much or use a really aggressive solvent like brake cleaner and you take out the paint, too.

Begin by heating one corner of the marking with a blow dryer, heat lamp, hot water or heat gun until hot to the touch.
Pick up and lift that area you just heated (use a razor only on glass surfaces). Slowly begin pulling back the decal, at less than a 90 degree angle. Continue applying heat to the area just before the area that is being removed.
Once you have removed the marking, check to make sure that all of the adhesive residue has been removed. Remaining residue may be removed by using Isopropyl alcohol (rubbing alcohol).
(source: http://arcadvisor.com/faq/apply-vinyl-label-decals)

If I did all that I'd never get done with the job. It would take longer to the the bleeping labels on than to do the study. Certainly not worth the effort. Just put the new label over the old one and be done.

bbaumer, I was addressing the original question from sam314159

It's really not that slow. The glue softens almost immediately with a heat gun. It peels up pretty quickly.

I don't have a good photo to show but I've seen panels with multiple labels stacked not only on top of each other but also multiple VISIBLE labels on the same panel which needless to say makes it extremely confusing as to what the correct values are.

With damaged labels I'd go to the effort of removing them using the heat gun method described. For the others, I'd put the new label over the old. Of course, this assumes the new labels are as large as the old.