Quoted from PinballFever:
Wish I could get them off so I could put the new ones on. I'm afraid it'll break the bumper body in some way.
I got new flipper links from PBR and replaced them.
Still need to triple thick the backglass so I can protect it. Do you tape over the clear parts then immediately remove the tape after spraying or let the TT dry then remove the tape?
The danger is more likely breaking the caps than the bumper bodies.
I thought you were more concerned about breaking those. If you have reproductions to put on and weren't worried about the old caps (I would be) then you could almost cut them off with a dremel tool or coping saw, if you were careful. And even if something happened to the dead bumper bodies, Steve has those too or you could probably chase down a couple of original ones on ebay given enough time.
If you knew what kind of glue was used, you might have a chance that way. For instance, I always use Household Goop to hold my dead bumper caps (and inserts) in place. And if you get into trouble getting something off (or out) then you can take an eye dropper and use a little toluene to get the glue to let go. I had to call the makers of Goop to find this out.... but it was well worth it for the knowledge.
In fact, I underestimated the strength of Goop and put a small amount at 12 o'clock and 6 o'clock on the dead bumper caps to hold them in place on my Spot Bowler. Then, when one of the bulbs burned out... I couldn't get the silly thing off. I would have been screwed if I broke one of them. Luckily, I knew about the toluene and was able to lean the playfield (at the most extreme angle I could) against the head and could then drip some of this solvent down to where it reached one of the small dabs of glue. Then I would put the playfield back down... and gently pull back and forth until I could get it to let go. I had to do this for every one! Even with the toluene, I was afraid I was going to break or crack one of the caps... but luckily, I didn't.
Now, I recommend only using ONE small dab at twelve o'clock inside the dead bumper cap. VERY IMPORTANT!
I might as well get this information out here NOW...
Like Brylcreem... a little dab'll DO ya!!