I was just wondering how you could change the design or put a new design on the fret... markers. If that's what they're called.
if you're a handy person you can get a dremel or router (if it'll fit) and rout cavities for new inlays, but its not really that great an idea. to do it well you'd prolly wanna remove all the frets, pry off the fretboard, remove the dots(if you have something more intricate than a dot i'd just leave it) and then start routing. Depending on your skill with hand tools you could just pop out the dots and hand carve the channel for your new inlay. its time consuming but i've done many inlays that way before just because i tend to fear a couple of my routing tools.
Its really expensive work to have done. And is probably not something for a beginner to try. If your really handy with wood working tools and have the proper tools then may not be a big deal. But isnt something done in a few minutes so expect the guitar to be unusable for a little while. And if you botch the job would be a disaster.