I'd grab my Dremel with a small dentist bit in it and start cleaning out
around the stud so that I could get at it. Epoxy later can fill the hole.
Be carefull as the binding post may be soldered to a printed circuit board
rather than a wire.
Then, after finding the wire, solder to the wire a new binding post. The
binding post is probalby a 5 way post that Radio Shack sells.
Short of that, you probbaly don't have enough meat inside to do a good job
of drilling and tapping a new hole as just inside there is usually a smaller
section where the soldering is actually done onto the post.
Don't bother with the conductive epoxies as their conductivity isn't good
enough to do a good job of conducting the current that the speaker will be
using. Take the number of watts that the speaker is rated for and divide by
8 for the amps of current that the speaker uses and you may be supprised at
how much current that the speaker uses and consider that you go and buy low
resistance wire just to make the speaker sound good. Any resistance in the
path decreases the volume and increases the resonant points of the speaker
which makes it sound bad.
I'll note that the potting is to keep others from copying the design and
this really doesn't work all that well as there are edpotting chemicals
available for alll of the various hard potting compounds. It just means
that the copyier needs to be a little more persistant.

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Why do penguins walk so far to get to their nesting grounds?