hey guys does any one know how hard it is to replace rear differential seal on 01 a4 1.t q. It looks like its leaking on the right side. Or is it better to get it done by the shop... any information would help ..

 

You need the correct press tool to get the new seal in, you can take it out with a small pry bar or screwdriver.
The only hard part is you have to support the rear diff with a jack and lower it down about 4-5 inches so you can pull the axle shaft out.

 

Alternatively, if it is a small leak, you can just check the differential fluid once a year and top up