A good way to get a seal out is to drill a small (1/8th) hole in the metal part of the seal. Use a small slide hammer with a sheetmetal screw in the end. Screw the screw in and use the slide hammer to pop out the seal. Just don't drill too deep and make sure you clean out any metal shavings. Use a little grease on your drill bit to catch most of the metal chips. You might have to do it a couple of times on the same seal, but it beats prying on the shaft and bunging that up.
