I am noticing oil leaking from the front crankshaft oil seal area. I have 140K miles on my plymonth voyager. My question is....when I take it all apart to get at seal, if the shaft has a groove in it from the old seal, is installing a shaft sleeve a big deal? What tips are suggested to installing a sleeve?

I found a link to installing the sleeve. Here it is.

http://www.alliedbearings.com/mfg_prod/seals/cr_speedi/cr_speedisleeve_install.pdf