First I would like to say that this only works with Doritos codes, since they can be used twice.

1. Make sure that you have an account on DewXP that has 1 time used Doritos codes redeemed on it.

2. Then:
-Make a new tab
-Go back to the website
-Sign out on the new tab, but remain signed in on the old tab.
-Make a new account using a different email

3. When you have successfully done that, you should have a tab open with your original account signed in to the page where it shows your redeemed codes and a tab with your new account signed in on it.

4. Now comes the easy part.
Just simply copy the used Doritos codes from the original account then paste and redeem them on the newly created account.

5. If wanted, you can also trade over your combat cards from the new account to add to your original collection.

6. Reap the benefits and enjoy!

This works due to the fact that DewXP doesnt make you add a specific account to your DewXP account.

So when MW3 is released, you can apply the time from both the accounts onto one XBL/PSN account.

Thanks for reading!
Thank and rep if this has helped you!