To all of those who have downloaded the Escalation Map Pack, you may notice that they have patched the Sign In method and require you to buy it when selecting CALL OF THE DEAD.

I believe I am the FIRST PERSON to find a workaround for this (I have been checking forums, threads)

To get the map(s) to work, follow these steps:

1. Sign In with King of Crack at the black ops main menu (with 2nd pad)
2. Play a SplitScreen with both accounts still signed in.
3. Play until you get an error "Invalid Gamertag" (I think you have get downed by zombies and it auto-restart)
4. Press ok, you will see Please Wait in bottom corner then it will go the main menu. Then it will say Please Wait again. Now Press ok and get ready to sign out of King of Crack AS SOON AS it says Please Wait again.
5. If done correctly, you will be able to play Call of the Dead on XBL!

Enjoy!

Note: YOU WILL NOT GET BANNED FOR THIS.
Note #2: Please credit me if you make a video on this. If it worked, please +rep