How difficult is it to replace the output seal in a transfer case? Can you do it from the outside with the shaft stub removed?
mines been spraying oil for awhile and I figured it would be a good time to replace it.

 

Are you talking about the seal at the end of the rear extension?

 

For rear seal, pull driveshaft out, pry out old seal, pop in the new. Toughest part (for the longer trucks) is handling the 2 piece driveshaft while removing the hanger bearing on your back if no lift is available.