Replacing side seals on 2l gearbox?

I have an 091 gearbox that's been leaking a bit so I have decided to replace the side driveshaft seals. What is the best way to get the old ones out? I'm a bit worried about damaging the sealing surface if I'm too aggressive trying to pry it out with a screwdriver etc. Also could I reuse the old bell housing paper seal if its not damaged or should I always use a new one or silicon sealant?
Thanks, Shane.