Changing Leaky Axle Seal

Guys, what am I up against attempting to change one of my rear axle seals (8-3/4") in my driveway?

I've never done one.......done my share of brakes, and have changed a couple of axles......but have never changed a seal........do they need to be pressed in?..........hammered out?..........nightmare?..........piece of cake?

Help me out here before I go taking it apart...........................