Rear axle is probably sealed on an 81 Newport but front is not unless someone modded it.
Just remember to tighten everything back down to torque specs on reassembly and check the spacing using plastigauge.
Some other very helpful tools to have around:
Manual impact driver with large flat head tip and hammer (to remove bolts that house pucks and sometimes the tranny cover bolts as well if it's the first time)
Red loctite for reassembly of the above (just the pucks part, not the cover bolts)
Wooden work bench or stool with a hole in it (to rest the gear with the pucks on so the shaft protrudes through the hole and you have a flat surface to work with)
Breaker bar for that pesky reverse-thread nut
Deep 15mm and deep 24mm sockets
New tranny cover gasket (oem preferred)
And of course, if you have access to the ZA50 clutch holder tool it makes life a hell of a lot easier(edited)