See Your Doctor. Go and see your doctor, usually after a little numbing medicine is applied, they can be painlessly cut off in the office.
In all honesty... ...I discourage people from doing this because of risk of bleeding, infections and scarring. That said, if you're going to do it anyway, clean the skin and a very sharp pair of small nail scissors with alcohol, and snip them off. Big ones can bleed quite a lot, so let your doc do those. An old folk remedy is to tie thread or dental floss around them, but that seldom works.