Do a couple searches on here for more detailed info but it is almost a straight drop in.
-Keep your 5.3 intake and injectors.
-You will need a tune
-I think you use the Flex plate from the 6.0 (double check that one)
-And look into some tranny upgrades unless you can keep from beating on it.
If either of you are in the Western PA area I have a 6.0 (LQ4) with 50-55K on it. I bought it last spring when I thought my 5.3 was on it's way out. Opened it up to verify no issues and put it back together and painted it. Long story short my 5.3 lives on so let me know if you are interested. I also have some parts for the install that just make sense to do when you have it apart but as of now the engine is a stock 6.0 with fresh black paint.