[TR] pinion oil seal

[Dave]

Hi, all.

Ibm being brave here and venturing into new territory.

a recently acquired tr3b is leaking oil out of the bfrontb or forward side
of the diffy.

according to the moss parts book (and with a little help from a friend), I
need a new oil seal.

that would be mossmotors part 520-090, #26 on this diagram:
http://www.mossmotors.com/Shop/ViewProducts.aspx?PlateIndexID=36462&SortOrder
=540

my question, since I have never done this before, is do I need/should I
replace anything else?  and any hints/caveats would be helpful.  I do have the
shop manual.

thanks!