What is the best way to kill the archdemon in dragon age origins

All you have to do is when you get to the archdemon fight make sure you ether have a strong mage or a strong archer then put the mage/archer close enough so that the archdemon doesn't fly after you but further enough away so the claws can't get you then just keep shooting or casting until it flys away then kill all the darkspawn until it comes back then repeat.

note:Keep party members away unless they are archers/mages you'l need them if you die.

note:have lots of health potions and if you are a mage lots of mana potions