Saw there was an old thread like this, but it was closed so...
So, I can't stand this guy. Normally he is unkillable of course, but with the help of a killmove mod I managed to get away with murdering him. I planned it for a while, leveling my character until she was a crazy strong orc brute. Then I go to Windhelm for the first time, watch Rolff and his buddy berating a dunmer. When they finish and go walk over to get a drink, I challenge Rolff to a brawl. He accepts, already pissed off and confident he can win despite the fact I tower over him.
He is unwittingly led away from the open streets to a dank, dark alleyway. We pass a murder scene on the way. I finally lay into him when we're close to a wall, bashing him relentlessly until he's doubled over. Having lost fair and square, he then has the audacity to complain that it "wasn't a fair swing."
Fueled by anger at the general dickishness of the man before me, I execute my finishing move. In front of a few onlookers who followed to watch the brawl, I pull up Rolff, plunge my hand into his chest, and rip out his heart (surprised he actually had one really). Of course the nearby guards pull out their weapons and demand I pay for my blatant murder. So I did, with 1000 septims. I had amassed a lot of cash at that point so gold was no barrier for satisfaction. The guards then walk away with their money while I strip Rolff of all his stuff and dump it on his fresh corpse.
Finally, I exit Windhelm with my bloody trophy in hand. On the way out I kill Rolff's partner in crime for good measure, crushing him with a few blows from my warhammer in a dark corner. All in all, a good day's work.
(Shortly after I was out of Windhelm I was assaulted by a few hired thugs, apparently sent by Galmar Stone-Fist to get revenge. I guess word spread fast.)
Lengthy murder expose aside, how did you kill Rolff? If you could, that is.