How to rotate a bone I am following a tutorial about how to make a simple stick man. Everything went fine until I reached bones. To follow the tutorial do I need to rotate all the vertical bones.

On the image I selected all the bones I need to rotate. I need them 180 degrees rotated.

(if you don't understand what I mean, here is a screenshot of the video)

Can somebody help me with fixing this?
the tutorial is telling you to set bones in the wrong position and then reverse many of them? anyway, you are in pose mode, that is intended to use when the rig is correct, and you wish to animate it. to correct the armature, you must me in edit mode... 

so, select the armature, go to edit mode, select the bone gone wrong, press W and select "switch direction".