I've had it done twice and they leave big-ish scars, but you feel no pain during the op, and only a tiny amount of stinging afterwards for a couple of days at most - it's usually just a little uncomfortable and nothing more though. The fact it leaves a decent-sized scar shouldn't matter too much if it's on the side of your face, like mine were. The scar is well worth it.
They inject a local anaesthetic into the immediate area, then cut it out (and it goes DEEP!). All you feel is a load of tugging though. Then they sew it up, and you get the stitches removed about a week later.