I'm guessing (all?) the above people thought you meant just replace the entire diff housing as a complete unit. This is, as stated, not technically difficult. If, however, you are contemplating replacing the LSD hemisphere, crown wheel and pinion, into your housing, then this is much more difficult. Sometimes you can be lucky, and the two lots of shimming will just swap over. If it doesn't, and if you don't get the two lots of preload correct, it will die rather quickly.
If you're not driving a manual you're really just steering.