Since the pin you want to use is a different TPI (threads per inch) than the original, you'll need to bore out the old threads, plug the hole, then drill and bore out a new hole for the new pin and tap it for the new pin type. Then yes, you'll want to use epoxy to adhere the new pin. Be sure to cut glue relief slots in the lower portion of your pin to reduce the chance of cracking the forearm due to hydrolic pressure build up when installing it using the epoxy. If you would classify yourself as a beginner at cue repair, you may want to practice this procedure on a scrap dowel first. You may also want to consider buying Chris Hightower's dvd set on cue repair. It's a terrific place to start.
Mr H