This is what I found to show you what a complex job this is https://www.youtube.com/watch?v=sWhfvTfvCGw and what it might require also I'm not a master mechanic like Scotty and unless he had the car infront of him I doubt hes going to be able to coach you on how to change it from a forum post.

If your going to attempt this for time the main thing is be CERTAIN you put the right diff fluid back in! Its not like regular oil and some cars take special fluids beyond just a very heavy weight oil. Check with the dealer on what fluid they recommend and use that oil ONLY. Differentials are pretty simple but if you've never done one before you need to be really careful and the only other major thing is check the old diff fluid for shavings. As long as all the gear still move freely inside the diff you should be fine putting it all back together. If you see metal it might need to be replaced altogether so just pray you don't see any metal. Only other tip Scotty usually recommends for big jobs like this is take pictures so you put everything back together right after you reseal it up.  

This is not a repair someone can typically do in their own garage without significant car repair experience.