You can do it yourself if you are so inclined with a skil saw and a granite blade. The only downside is you should use water to keep from heating up the rock and to keep the dust down. I was able to buy the leftover from my kitchen and used them in my Laundry room. I cut the hole out for a sink with a worm drive skil and a lite drizzle from a garden hose. When it came to the corners I used a porcelain tile blade in my jig saw. Worked great. You could use one of your dental drills but it might take a while.
I do believe there are special tools to do this. Our counter tops were installed by a company in your area called, Contour Countertops. They were awesome to deal with and sold me the remnants for a steal.
https://www.google.com/maps/place/Conto ... 22.2958063