I used a big arse socket to tap them in as I didn’t have a seal driver large enough. The correct tool would be a seal driver. The blue stuff is just the paint from the seal casing...not RTV.
Csb above mentioned o-rings and he is correct. There is also an o-ring that goes on the tailshaft of the automatic trans that goes inside the sleeve. It is usually a good idea to smear some gasket material inside the sleeve threads as well. Between these two seals and that o-ring is probably where your leak is. Replace them all at the same time.
Here is a good place to view the gaskets and other goodies. Thanks Billhilly for the link!
http://www.quad4x4.com/New_Process_NP205_Parts.html