WWE 13

Another easy achievement here!

To get the achievement just choose "specialty" in exhibition and then championship match. Choose whoever you want to defend it against and the superstar that holds the custom belt.
Once the match has started get out of the ring, and go over to the announce table. In the bottom right you can see the title, just press the LB button (sometimes it will pick up the chair standing there, just throw this one away) and you will pick up the title. Now head over to the opponent and give him a good swing with it.
*ping* achievement unlocked!
Remember if you don't want to get DQ'd remember to turn this off before starting the match!



To make a custom belt:
In the main menu go into the "my wwe" menu and then choose "title management".
Once in that menu click the RB button and choose an empty slot, this will take you into the editor. Once there you can choose the base, basically it what championship you want to edit. Then you can change the collar of either the plates or the straps, then you will get the where you can choose what name you want to give it, set it for superstar or diva, single or tag, etc.
Once done there just save it.
Then you will get into the "title management" menu again and you can assign the title to a superstar there.

The UKGamingBureau have done a very quick and easy to follow guide on this achievement, if you're still unsure on how to get it, I would suggest it. Happy gaming!