I haven't been in there yet but if it's similar to every other bike I've owned you should be able to get a seal remover (curled pick) in there and pull it out. If that fails you can deform the outer metal casing with a screw driver and a hammer. Tap lightly until the OD of seal is deformed enough to get some neddle nose pliars in there and pull it out.
Look at the new seal and you'll see what I'm refering to.
John