Rear axle seal replacement

Okay, this the situation: i went and checked a customer's car out, i got in the passenger seat and noticed a sound when the rear wheel is slowly turning it didn't sound like the wheel bearing itself. so she parked it i jacked it up and took the rear drum cover off on the passenger side and noticed a lot of gear grease was coming from the middle area. in my head i am thinking the seal may just need to be replaced, at the same time i am thinking about changing the bearing too. i don't have access to any press equipment, but i am confident I can change the seal and see if that solves that problem. i just wanted some advice on removing the rear axle on this particular model because i was told i don't have to take the differential cover off just use a slide hammer. let me know what is the proper procedure. thanks