finding skulls in halo 3?

[kevandcambria]

When you back to the levels you already beat during a campaign, are all the enemies still dead or respawned, cause i wanna know the best way to find skulls in halo 3

 

[chris]

The enemies are always there when you do a mission again. If you're going for the skulls, you need to start at the beginning of the level and do the entire mission too!