×He will accept silver, gems, golden things

×You don't need to kill him, just to land a blow.

×You need to bypass his shield. The method depends on your class.

×The staff breaks his shield, and he runs off. Later, he's on the bridge in Svartalfheim, but he doesn't cause you any trouble, since you don't have to cross the bridge. Be sure to get a look at his new shield

×Convince him there's some weird piranha under the bridge. When he moves his shield to look down at the piranha, throw a dagger at him and he'll yelp and run away.

He won't fall for the piranha lie twice. If you already used that conversation option, you'll have to do something else, like pay him. He'll accept the cursed ring in Advari's house, and it reappears in the house after you give it to him so you can use the same ring twice (just go back and pick it up again).