Finally replaced it today. Seal number is 8644709!

I didn't need a extractor tool in my case...actually the seal had moved towards the selector rod actuator by itself and I guess this has caused the leak. The seal had totally hardened out

The most difficult part was getting the new seal in place. Using a 14mm socket with the help of a lever against the 4wd drive axle is the best option in my eye. Pushing by hand or hammering did not lead to anywhere.