I killed one at level 5 in light armour, how you ask? I simply unrelenting forced him of the cliff side. But then of corse there may not be a giant drop near by? Equip your most balanced fast/powerful one handed weapon, (sky forge sword if you have one) a shield and a follower you should follow a simple patern of block attack block attack in your heaviest armour allowing your follower to take free shots, use paralysis poison if you have it, whilst using any potions of healing you own to stay on top, remember to possibly stop its attacks by bashing it with your shield, if all else fails run! Perhaps let it follow you up to high horothgar and let it get UTTERLY DESTROYED by gray beards if you want a good laugh, I did that, first they shouted YOL (fire) at it then hilariously beat it to death while it was unconscious with there bare hands

I killed one at level 5 in light armour. How you ask? I simply unrelenting forced him off the cliff. However, if there's not a giant drop nearby? Equip your most balanced fast & powerful one-handed weapon, (skyforge sword if you have one), a shield and a follower. You should follow a simple patern of block, attack, block, attack in your heaviest armour whilst allowing your follower to take free shots.

Use a paralysis poison if you have it, whilst using any potions of healing you own to stay on top. Remember to possibly stop its attacks by bashing it with your shield and if all else fails run! 

Perhaps let it follow you up to High Hrothgar and let it get UTTERLY DESTROYED by Graybeards if you want a good laugh, I did that, first they shouted YOL (fire) at it then hilariously beat it to death while it was unconscious with there bare hands.