Bartender.

[Lakweeta]

I've got my bars setup exactly the way I like, I just can't figure out how to keybind them :/... It says something like /bar bar2 hotkey (set to on or off) which I set to on.. Then I'm lost ;-;

[Melancholia]

Open your normal keybindings tab, Further(scroll down) down you'll have the bartender tabs - key set-up.

[Hyunckel]

I set up my keybinds thru blizz's interface, bottom left = bar1, bottom right = bar2, and so on.