There are a few ways it's done... I've heard that the battery acid technique is the worst, but laser and sand blasting aren't fun either. I've never had one off, and I only have one (or two counting wedding band tattoo). I'm thinking about having a piercing closed up, and it's going to be some real pain. They'll have to cut the skin all around it, and stitch it together. And no, I'm not sorry I had the piercing for 20 years, and nobody better ask you if you're sorry for getting the ink.
Charles