note, you omni nubcakes can't do it.
first, grab yourself a sacrosanct sword staff, preferable a brawl upgraded one.
second, cast watch ward
third, get someone who isn't likely to ld to team you for awhile
fourth, go inside, fight him, run back and forth across his pf, firing perks when you need to turn around, ward will block pretty much all the hits while you're turning and he won't hit you in the straightaways. use perk heals to make up for if he does hit you. once he starts fearing you need to pay a bit more attention, the adds are a bit difficult aswell.
anyways, have fun with that, didn't need anything off him, just did it for kicks.