Pilot Archive

I'm on phase 2 of this quest where I have to defend the starport from rebels and wookies. Only problem is that some of them keep spawning on the hill where I can't attack. If I don't kill them all, I can't finish this phase. Anyone know a way around this or do I just keep trying? I've had to let the last attackable npc kill me to reset that phase and not have to go to the bones on dath again...gettin pretty old fast, lol. Thanks for any advice.