How do I add a second row to the action bar?

[WingedEspeon]

Mostly what the title says. I have run out of space on the first row of the action bar and I have a new skill that really needs a place on the action bar.

[Micbran]

There should be a button down in the bottom right that looks like a closed lock. Clicking it will turn it into an open lock and allow you to manipulate your UI around. Drag your hotbar up a little and then right click it and drag down to expand it. Then, once you've finished moving everything to your liking, you can click the lock again to set the changes.

Alternatively, you can press pg down and pg up to cycle between "hotbar pages" or whatever you wanna call them.