Adding another gamertag onto xbox 360

My son was hurrying me when putting in codes. 1 to renew his subscription, the other for me to start playing together online. I did not see instructions on adding me to his established xbox360. I see his gamertag. How do I add mine?

:)

 

Borderlands 2 DLC cheat?

I'm trying to figure out if a rumor that I heard is true. Can you download DLC for borderlands 2 onto one Xbox (let's say Xbox A) under a gamertag, and then go to another xbox (Xbox B) and download it with the same gamertag because the DLC, I'm assuming, goes with the gamertag. Now the question, after I've done this, will Xbox A still have the DLC on it for another person to play since it was the 1st console to have the DLC? A friend of mine told me that this could work, but I'm not sure so I'm asking around.

Thanks

 

Headsets ?

Adding another 100 dollars onto the pricetag of my Xbox One for a new headset will go over like a lead balloon with my wife... maybe Tritton will make a less expensive headset?

 

Do a gamertag recovery. Turn the xbox on, hit the guide button and press x to sign him out (if he's signed in). Then select sign in, then download profile. you will receive prompts to enter your email and password. Once your data is entered, sit back
and your profile will download. Once that's done, (from one xbox dad to another) you're free to put a serious cramp in junior's online gaming style. Have fun!