How to defeat Grand Moff Kilran?

I'm the wrong person to answer this, because i did this years ago.

I remember, as a ranged class, you need to run up to him, get close to him to push him out of his "sniper stance" (= hiding behind his barrier, same as all player snipers do). On the way to him you need to avoid his heavy hitting shots by running around a corner to break line of sight. Hope this helps somehow. I only answered because no one else with better knowledge did. Maybe search for a youtube video.