Pip

Aren't birthmarks and moles pretty much the same? Anyways, I've had a few of the annoying brown spots removed when they started itching or generally behaving like OMGCANCER!!! It's a pretty easy procedure. The doc gives a local anaesthesia, then cuts out the mole and stitch the cut up. The only thing you'll feel really is the prick and burn from the anaesthesia and maybe some itching from the healing cut. But that's it, nothing to worry about. Since it's (usually) a tiny cut and not very deep, it heals real fast and neat. So don't hesitate to have a birthmark removed if it's bothering you.

The stitches either come out of their own or you (or a friend if they are in an awkward place) can remove them yourself, and you should avoid getting too much direct sunlight on the scar for a few months.