Solar panel survive hail very well. In order to be UL listed they must withstand 1" hail at 70 MPH. I've talked to a guy who got to fire the ice gun to test them. Rock are a different story. Also, perhaps, these weren't UL listed panels.
If these panel are made like the ones I'm familiar with you won't be able to remove or replace the glass. It is tightly bonded to the cell material underneath. There's no way to get them apart without further destroying something.
As much as it hurts, the best bet is to just replace it.
I've had to do this with several panels that got damaged on people's roofs from falling trees and the like. One guy had the wind rip his whole barn roof off and took his solar panel with it. I've also had a few slide off the back of the truck on the way to a job. I tried the "replace the glass trick" but it can't be done.
