Pulling a seal can be maddeningly frustrating if you go at it the wrong way. The wrong way includes using nothing but a screwdriver and a lot of cursing.
Here's the right way. Tony grabbed a seal puller from his tool arsenal and worked the seal off from the inside lip. Tugs on the seal puller were interspersed with a few judicious raps of a hammer and a small cold chisel on the seal's outer edge. These forces on the inside and outside of the seal eased the seal out of its bore.
It turned out that thousands of hard miles had worn a groove into the drive flange's seal journal. There are two ways to fix such a problem: either use a repair sleeve or replace the entire flange. Tony went for option two and replaced the flange.