Doom 3 Hell levels

How do I beat the Guardian, and where can I find the seekers or the weakness of the boss? Does anybody know how to get passed this level?
Thanks
Laters

I have the collector's addition for X Box, if it helps for information purposes.

i couldnt help you i just bought the game myself and only being on the first few levels

Farthest i've made it is hell 2 or 3. Ain't stuck or nothing just haven't played it. Been bustin out on live wit etrain

Shoot all the flying demon flashlight guys that follow you around, the monster dude will open a crazy portal thing to summon some more. While he's doing that, blast it with your WMDs.

Thanks y'all.