Attack the crystal on his head to stun him. Now trip him by around and pulling either of the chains attached to his feet. Start cutting away at his head. This method will save you arrows.
Shoot the eye on his head with arrows until he falls. Now run up and start slashing away at his head before he gets back up. He will then start falling with only one shot. Repeat until you win. Check pots around the room if you run low on arrows or health.