You can't.
sr 130
Yes. He used to have Spartan 2 armor, but now he has Spartan 4 armor. It's armor, now with Armor Abilities!
Yes, I on some missions in Spartan Ops
The first player is chief and the second is spartan 4
Unlock it as a Spartan-IV at Level 12 I believe
Yes, in Halo 4 you play as Master Chief and soon find other Spartans (Commander Palmer is the leader of them)
Halo 4 will not have "survival mode" (by the way it's called firefight) like Reach and ODST, but it will have Spartan ops, which is essentially a second campaign based on a spartan other than Master Chief.
There will probably be a halo 4 and if there is yes Master chief will be in it because if you complete halo 3 on legendary you see that he survives in cryo sleep. =]
Both players will be Master Chief.
A Halo 4, also known as Halo: Reach, will come out in the November of 2010, and no, it will not follow the Master Chief's story. You assume the role of a SPARTAN-III.
If you preordered Halo 4 and have the assassin emblem code, you can use it by going to your spartan's emblem and looking for it in the foreground option.
343 Industries has stated that multiplayer will focus on Spartan IV's NOT Elites. Elites will not be playable in Halo 4.