I answered your PM.
One thing I should have mentioned...do you have a replacement seal? I expect you'll find the seal to have a metal backing plate (or thin plates sandwiching the rubber). Most of them are good for a one time use. Also, just having the replacement seal may help you figure it out. I'm pretty sure you'll have to use a screwdrive or other flat type bladed tool (two of them, actually) to pry it out. More then likely, there is a bearing on the other side of that seal. Although that bearing may require replacement too, don't go ballistic and destroy it when you pull the seal. You may need it.