Shouldn't be too difficult. You will wand a pan under it when
you pull the drive shaft out as the fluid will come out the end when
you pull the driveshaft. I always use a screwdriver and pry
out the old seal.
Before I retired I worked at a plant that installed tons of seals in the product
that we sold. We always put lube on the rear of the seal where
the spring is. We always packed it full.
At home I use regular grease. I never install them dry.