Its not hard to fix. What axle do you got thats leaking?
Dana 30/Front Dana 44. You have to pull both wheels, breaks, hubs, and shafts. Then pop the carrier straps off and remove carrier. Seal is located between the carrier bearings and inner tube.
Dana 35/Ford 8.8/Chrysler 8.25. Remove diff cover and C clip for what side is leaking. Remove tire, breaks, shaft. Oil seal is located on the tube. Pop seal out and replace.
Rear Dana 44. Remove tires and breaks. Remove 4 bolts that bolts axle to the tubes. Cut the seal, spacer, and bearing off. Press on new seal, spacer, and bearing.
Im doing the rear axle seal on my AAM 11.5 this weekend