I finally got around to swapping the pulley this past weekend. I went to the local Autozone and borrowed (for free) a universal three-jaw puller. The pulley came off with ease and the new one slid right on. I tightened the nut by hand with the same tools used to break the nut loose, so it should be tight enough.
After reading about the alignment issues some of you have had, I paid particular attention to how the belt rides in the pulleys. So far, so good.