in halo 3 online how do you unlock new helmets and armor?

[Bears4Life]

under appearence on some helmets it says locked how do i unlock them>?

 

[IAmNotANugget]

You have to find the skulls in the campaign mode except one set you get when you receive all 1000 gamer points.
Here is a link to the skull locations.
http://www.halo3planet.com/halo-3-skull-locations/
There are also video guides on youtube.

 

[IAmNotANugget]

You have to find the skulls in the campaign mode except one set you get when you receive all 1000 gamer points.
Here is a link to the skull locations.
http://www.halo3planet.com/halo-3-skull-locations/
There are also video guides on youtube.