I have a Fender 12-string. I found that the high E-string (the string closest to my chin) was buzzing against the frets. For some unknown reason, the bridge has started leaning toward the sound hole, reducing the action. I talked to people at the local music store, they said the fix would be to remove the bridge and glue it back on.

They could do this but the cost would be something like $200-300, more than the guitar be worth.

They said they would use use heat to soften the glue and it would come loose. I'm trying to think of how to do that. Here's one thought:

Get some sand, wrap it in a square of aluminum foil, stick it in the oven for 15 minutes at say 350 F, then put it on top of the bridge and press down so the shape conforms and the heat transfers evenly.

I wonder if this will turn the varnish black around the bridge, or some other disaster.