How can I fix a garbage disposal with crushed glass in it?
The easy way: remove the large shards with tongs.  If you're having a hard time, cut up an old kitchen sponge, make sure it's soft (moist) and put it in the tongs as a bait for all the glass shards.  They'll stick in the sponge just like they would your hand.  Then, just hope that the small pieces will go down the drain with time.

The hard way: unhook the disposal (turn off the power first), take it outside, turn it upside down, and really work on it with a garden hose.  Wear gloves and verify by operating it via the screw on the base to make sure you got everything before you take it back in.  Don't do this anywhere someone would go barefoot.