Larry,  steam can be used to swell the wood fibres.  A dampened
cloth and an iron will reduce the dent if not restore the surface.
Any remaining depression can be filled in with an artist's brush
with shellac or sanding sealer.  Then fine sand paper and a hard
block to level.

I use a hammer iron.  The tip of a clothes iron will work.  Do not
get it too hot or too wet, the glue will soften and you will have
another problem.  Practice on a scrap to get a feel for the process.

Have patience,

Jon Page
Harwich Port, Cape Cod, Mass. (jpage@capecod.net)