Don't feel too bad, I've been doing this for years and I'll still break an ear or two now and again!
Do you have the broken pieces? The simplest fix is to super glue it back together and fill the gaps with Propoxy.
If you don't have the pieces you can resculpt the ear using propoxy (which is just a fancy name for plumbers epoxy you can get at any hardware store) or if your skill level allows it, resculpt the ear in stone. This works best if it was cast in Ultracal, but you can make hydrocal work with some practice.