I just did mine , No problem , you just buy a similar year LSD & bolt it onto your existing crown wheel, buy new set of side bearings, theres a few tricks in getting the right preload between the crown wheel & pinion & also between the bearings , I think theres a DIY on this subject in this website, with pictures to show the steps. Make sure your diff has the same carrier bearing setup , IE, some have internal shims & the newer type have external side threaded carriers (no shims) so you can adjust the preload from outside the diff , which is very handy , you dont have to take the cover off the diff housing at all.
Probably easiest to swap the whole diff than open it up. I have seen reco LSD diffs on ebay for around the $800 mark with whatever ratio you want installed. I can recommend you consider getting a diff with a different ratio from standard. I went from 3.08 to 3.89 in my VS and it was the biggest improvement in performance. A little research on the forums will give you all the information you need should you wish to go down that path.