You can find some information over @ StewMac's page on
http://www.stewmac.com/freeinfo/I-5350.html
I didn't quite have the same scenario, but I did recently replace the nut on an Epiphone SG guitar. It was actually easier than it looked. I used the blue painting tape (it's the same as regular masking tape) and applied that on the headstock above the nut and on the fretboard under the nut to prevent chipping. Then, I used a chisel, about an inch and a quarter wide, held it nearly parallel to the fretboard, gave it a few taps and off it came! I used a bastard file to get rid of the excess glue that was already there, applied a few drops of superglue, held it in place for a few seconds, reapplied the strings, and it was as good as new. Also at StewMac, they have some different materials you can use for a new nut, and I believe they have some pre-cut nuts that might suit your fancy. Anywho, good luck on the project!