Pull the cad hosuing and fork, then the collar, knock the seal out after the axle shaft is out, pull old seal out and put new seal in on driving mandrel and use threaded rod to pull in. Use only a oem mopar or timken seal (or in pick skf). Do not use a National seal- they got the dimensions wrong

Can buy this, but he sells just the mandrels also and get the threaded rod/nuts/washers at the hardware store. Mandrels keep it straight. Hard to navigate his site now since he screwed it up...
http://www.quad4x4.com/cgi-bin/commerce.cgi?preadd=acton&key=884620

Limited pics of how I did it here, 3/4 way down page
http://ramchargercentral.com/mopar-trucks/1999-w250-project/