Or you can get a copy of Hideo Kamimoto's Complete Guitar Repair book and do it yourself or see if you think you can after checking Hideo's techniques out. He's very basic and allows you to find a few things out for yourself, but that works well too. Fretwire you can order in from Stew-Mac. Other than that all you need is a couple small files, finegrit sandpaper, a fairly good straight edge and very slow and thoughtful movements. If you're scared send the guitar off somewhere but get his book anyhow. I'd never done a fret job before and used him for guidance when I refretted my pawnshop rescue Fender electric with Jumbo fret wire. When I got it the neck was pulled into almost a U shape and played and tuned terrible. Hideo's book helped me to somewhat better understand the inner workings of the thing and I managed to make it into a good sounding and playable guitar. If you're only replacing four or five frets you should be able to get along alright, mebbe even get an elcheapo to experiment with before pulling the teeth on your Martin. He's a good teacher, even if only from a book. For more inspiration check out Kathy Matsushita's site HERE. She makes everything look easy!