I've heard that if you have a CD-Key, you can go to Blizzard to download the full game from them.
I want to do this because my CD-drive is refusing to open, and I don't wanna break it open.

Has anyone ever tried this method to get the game? Or is it just impossible in the first place, and I was mistaken?

I've been looking for someway to do this, but I can't find anything on the Blizzard websites.

You gotta bind the key to your battle.net account (formerly blizzard account) then you can download it.

Yeah its easy, it will give you like a 26 online key and you just use that when you get the game from battle.net.

Alright, I got it to work.
Thanks for the help guys.