Stitches usually stay in for several days to a couple of weeks, depending on how bad the cut is and where it's located. Your doctor will tell you when to come back to have them taken out. Removing stitches is a much faster process than putting them in. The doctor simply clips each thread near the knot and pulls them out. You may feel a slight tugging sensation, but it shouldn't hurt at all. You won't even need an anesthetic.
Although removing stitches is not a difficult process, you shouldn't try to remove them yourself.