Tip top replacement is pretty straight forward. I don't know what it would cost you to have someone else do it, or where you would take it. I would suggest doing it yourself. The hardest part is going to be getting the exsisting tip top off. If tip top cement was used by the factory (which I kind of doubt) gently heat with a match or lighter. Be careful to only heat guide so you dont burn the rod. With a little heating the tip top will come off if tip top cement was used. If epoxy was used I don't have any really good solutions except cutting the rod off at the tip top. I know this doesn't sound like a very good answer - somebody out there might have something better? You will only lose 1/2" or so of your rod. Replacement tip tops can be found at many of the larger tackle stores. You will have to bring your rod in with the tip top removed for the proper fit. I would reccomend using tip top cement to put the new guide back on instrad of epoxy so the next replacement will go easier. This is the same stuff the arrow fletchings are glued on with. Sources for guides: Outdoor Emporium, Patricks Fly Shop, Kaufmanns Fly Shop - there are others if none of these will work for you.

Steve