Coming back later might be the best option if you don't have the necessary equipment hitting power to get through.
Hit and run tactics can work here, if you can succeed in drawing out his minions one or two at a time they shouldn't be too hard to deal with. He can be a handful though.
Personally I usually make sure I have at least one killer potion that paralyses, does lingering health damage and health damage, which I use on my first bow shot on him; which usually kills his mortal form.
Another option is to go out and come back with reinforcements, you should have Lydia available by now at least.
[QUOTE=Darth Gavinius;1096098]Distrbution of games, is becoming a little like Democracy (all about money and control) - in the end choice is an illusion and you have to choose your lesser evil.
And everything is hidden in the fine print.[/QUOTE]