There is a lot of garbage out there on the internet but these two videos on installing a nuc and a package are pretty good. Made by our friend in Maine, Erin Forbes of Overland Apiary. Here she installs a nuc (note she has a lit smoker in the background just in case)
https://www.youtube.com/watch?v=mB7Vab9hxmg
and a package (Note she fiddles with the queen cage- I like installing the queen cage first, but any way you do it works- and she says that too! What does not work so well, is using your hive tool to take out the cork- try a small nail or small knife).
https://www.youtube.com/watch?v=Bk0iFG7xorI