they are not too hard too change if you have the right tools. strap-on , ratco and cornhole tools all sell a kit that makes quick work of this procedure. if thats not availablenot then an air hammer will get it somewhat fast out or a b.f.h. will surely do the job. that same hammer and a drift will get it in.
i used this place
http://www.suspension.com/nissancars.htm to get my joints from. compared to the stock units i removed, the McQuay-Norris ones looked beefier, felt beefier and had a grease port. also the "bolt" part of the joint was about a mm or so bigger than than the stock one. but still fits in the knuckle spindle.