Try playing swat, or bring 8 people in slayer, and tell them to lest you win, besides that good luck, just stay with your teammates the whole time, and NEVER FIGHT 2 GUYS AT ONCE!
No, in Halo 2 you can not unlock armor.
You unlock the armor.
You unlock the odst armor by unlocking the UNSC SPARTAN achievement
You have to be an warrant officer in halo reach to unlock the helmet you also have to go to halowaypoint and unlock the armor.
go to http://hubpages.com/hub/Halo-3-Armor
To unlock Recon armor in Halo 3, you originally had to beat all of the VidMaster achievments, but the armor is now available to all players. To unlock the recon armor in Halo: Reach you had to pre-order the game and you would get a long (25 character) code for the recon armor DLC. To unlock the recon armor in Halo 4, you had to either pre-order the game or simply buy the armor with your in-game credits.
you have to get 49+ acheivments
yes you still unlock the armor. you and the player that your playing with unlock the armor. =] =) =p q=].
There is two ways to get it #1 unlock all of the armor #2 is to become the highest rank in halo reach
you buy it and you can unlock some by halo waypoint (free download)
Halo Reach armor is sold with a credit system which you earn credits in the game itself by playing. Halo 3 armor you must unlock with achievements and completing certain aspects of the game.
For now, no. Although, in the near future a new kind of armor might be introduced, much like Recon armor was in Halo 3.