Zitat von Adiuvo
6. Navigate to PSP/GAME/OEUPDATEMAKER, and move the newly created DATA.DXAR into:
// TAKE OUT ANY UMD THAT IS IN THE DRIVE!!!
7. Make sure your battery is at least 75% (100% recommended) and plug the AC adapter. Navigate to the Game menu on the PSP and start the application named 3.40 OE-A Firmware install. Howeveer, if you want to take a chance with a less amount of battery when starting the program hold L and Triangle to bypass the battery check.
8. It will display some pink text, press X, and it will start flashing your psp. A percentage will be displayed.