Instructions
Load your most recent copy of the "Yu-Gi-Oh! 5D's" game series for the PSP. Go to the main menu of the game.
Scroll through the options on the main menu to get to "Database" and press "X" to see this submenu. Go to the "UMD Recognition" option and press "X" again.
Follow the on-screen instructions to remove the game and insert a previous "Yu-Gi-Oh" UMD into the PSP. Close the UMD door and follow the instructions to have the PSP scan the UMD, then remove it and replace with the previous game. Repeat the process for any "Yu-Gi-Oh" PSP games you have to unlock their bonuses.