From cancer on about.com
First, do not attempt to remove Steri-Strips too soon. Always follow your doctor's orders -- even if the Steri-Strip is itchy or irritating. Removing it too soon could cause your incision site to reopen. Plus, you may introduce harmful bacteria, which can cause a infection. (Signs and Symptoms of Infection After Surgery)
Second, do not rip the strip off. The same logic that forces people to rip off band-Aids in a super speedy yanking motion does not apply to Steri-Strips. Why? Steri-Strips are much more adhesive than your standard Band-Aid, and you'll probably do more harm than good if you yank it.
Know that you can almost always wait until the strip falls off on its own. In fact, many surgeons recommend it. Showering and the natural oils of the skin will allow the strip to peel in time -- usually about ten days or so. Some surgeons, however, will tell you can remove it a certain amount of days post-op. Please note that this is a guideline: if you were told you could remove it at Day 7 and yet you can't, it won't hurt to keep on a few more days. As the days after surgery pass, Steri-Strips do lose their adhesiveness and begin to curl. Simply trim the curled edges, and within a few days the entire strip will fall off. (How to Care for Your Surgical Incision) Finally, If you find that you just can't remove it, your doctor can always do so at your next appointment. For more information about surgical recovery, please visit About.com Surgery.