Search:

The way I remove pins is to carefully drill out the pins (if you have a drill press) with a 1/16th drill bit, then use a 1/16th punch to drive out the brass rod.

Failing that, you could always...

For scales, horn is a bit tricky because old horn is sometimes fibrous. I'd start by cleaning it up with Mass, and then maybe using some high grit sandpaper. You may need to shave the area off though...