Hi-standard cylinder damage

I got a Hi-Standard double nine .22 revolver years ago in decent shape but the previous owner must have dry fired it hundreds of times The cylinder is supposed to be counterbored to prevent this but it's bad enough to make ejection difficult. I used a metal shaft the same size as the casings and pushed it through the holes to try and fix it with some success, but it still sticks. Would using a small file to remove some of the burr be ok or could it cause misfires if I remove too much? Does anyone know a web site that would have instructions on how to dismantle this gun and remove the cylinder? Thanks for any help you have, this forum has helped allot before.

The ironic thing is the owner who did it was a firearms inspector, guess he liked playing cowboy. To remove the cylinder would I have to drive out the drift pins holding the frame together? I don't have much experience with revolvers, I find them rather finicky.

Thank you very much rcmodel, you saved me a big headache. Oh and the handle part of the frame where it's is connected to the the rest of the gun by the trigger guard has always been a bit loose so when you shake the gun at the handle the rest of it wiggles side to side a bit. It seems the frame is something soft like alluminum so is it possible to tighten it up at all? It's at the pin in the front part of the trigger guard where the slop seems to be.