Reto has a nice page up on exactly how to change those split pins. Nice to have, especially with the clear pictures and diagram.

Update 10/14/07: I’ve gotten a few comments and questions about Fossil bracelets, which have arrows in both directions. I don’t have one, and Reto’s page doesn’t cover them. The best I could find was this page of discussion which says that the pins are removable in either direction, a feature they’re calling Smartlink. This page on Epinions confirms this, and the author likes the idea. So you should be able to just push it out either side.