To do this, do I just need to re-install Bitcoin-Qt, let it sync, shut it down, and then overwrite the wallet.dat with my back up from my external drive? When I turn Bitcoin-Qt back on, will I see my wallet and be able to sell/sent?
Yes that will work fine.
Thanks. I'll test it out.
I guess in old versions of Bitcoin-Qt you had to -resync or something after copying back in wallet.dat.
I just wanted to make sure you don't have to do that now.