Rachet32

I found an interesting way to do it. If you have a character with high stealth, first pick pocket admiral imp and take his stuff. Leave behind 5 grenades and make sure the rest of your party is far away (other side of town works). Then unstealth and run away. He'll explode and die. It'll start battle but just keep running away from the fight until it ends. Guards won't attack you unless they get hit by the bomb. Afterwards you can stealth back and loot his head. If the enemies are still hostile, you can alternatively save and re-load, they lose hostility for some reason.