Yeah I know, that's why I said twice, you need a patched wow.exe
I said that you needed a modified wow.exe at the top of the instructions, then at the bottom, a link to the patcher.
There's another reason I don't recommend using Laurea's addon. It's a good way to stop your growth and exploration, however if you aren't the type to continue exploring and come up with your own methods of doing things, by all means use the addon.
But if you browse around the lua file, you'll see code for other functions that might catch your eye and interest. And guess what? that's not the only lua file, there are dozens of others that control various things of the game.
Sure addons can take care of most of it, but the moment you get the addon, you stop looking for answers, but for me, if I start editing one xml/lua client file.. i tend to continue to look around on the other files and see what else i might find. With addons, it serves a function and that's it. no more, maybe less.