Steps

STEP 1: Link your Xbox Live account to your e-mail address. This can be performed on http://www.xbox.com by following the directions on the website.

STEP 2: Link your Xbox Live account to a http://www.bungie.net/ profile.

STEP 3:

Sign out of Xbox Live. For the service to work, you will need to remain offline for a 24 hour period. That means you'll have to go 1 full day without your Halo and Call Of Duty online. Hey, at least this gives you a chance to go outside for once! Not that we should be talking. What's happening during this period? If we unlock all your achievements at once, or you are playing a game online and suddenly get achievements in something you aren't playing, your account may be suspended for suspected cheating. This prevents Microsoft and Bungie from noticing anything has happened. After 24 hours, when you sign into Xbox Live, you will get all your offline achievements at once. Microsoft will assume you got them offline, and simply updated when you signed into live!

STEP 4:

Sign into Xbox Live on Halo 3. Remain signed in for up to 4 hours. What's happening here? You're online achievements are slowely being unlocked. Stay signed in so Bungie.net can't see that you weren't online when you got an online required achievement!

 

STEP 5:

Log onto your Bungie.net profile and unlock the armor in your profile!

 

You're done! 

Check out how many people have used this website to get their armor!