Skill Bar
Hero Panel (H)>Build (2nd Tab Down, Square/Hexagon Icon)>Weapon Skills. (3 more tabs at the top left.)
To UNLOCK new utility skills, you go to Hero Panel>Training. You use Hero Points (Skill Points, renamed if you were around back then) to unlock them.
To change the utility skills without using the panel, get out of combat and click the tiny semi-greyed line above the utility skills. Note you cannot change weapon skills. You will also have to unlock certain things if you are playing a new character.
thanks so much!