At level 8 with a Blade skill of at least 25 complete the quests with the Jermane brothers and when you get the sword from the quest Sin of our Farthers go to vindasel with a 5 second paralyze poison.
Now when you get to Umbra don't talk to her, instead hit her with a shock spell and poison the Honorblade of Chorol with the paralyze poison.
Strike her repeatedly while she is paralyzed and she should be dead.
Pick up the sword and full ebony armor if you like, but it will be weightless and cannot be removed from your inventory.