Things You'll Need
Instructions
Identify what version of the PSP you have. This is a very important step as without the right version, you will not be able to downgrade your PSP, and instead you may "brick" the device, and be completely unable to use software of any kind on it. The following method works with PSP 1000 and PSP 2000 models. To identify your PSP, you can either check the label on the underside of your PSP, directly beneath the "Select" and "Start" buttons, or you can remove the battery and look at its back. You should see the model type and specific version (such as "1002" or "1003") in either case.
Download PSP official firmware version 6.31 and install it onto your PSP. This can be done wirelessly by checking for updates on your PSP's firmware, or by manually downloading and transferring the file to your PSP using the USB cable.
Insert your Magic Memory Stick. Be sure to double check the downgraded firmware options you have available to you via your Magic Memory Stick, as not all versions will have all custom firmware.
Turn off your PSP completely by holding the power button down. Remove your current battery.
Insert the Pandora Battery. Once it is inserted, hold the "up" button on your PSP until the firmware options appear on your screen.
Select your preferred firmware and press "X" on your PSP. The installation will begin shortly after. After the installation finishes, you will be prompted to reboot your PSP. Press "X" and allow the reboot to take place.
Navigate to your PSP's System Information page by selecting Settings on the main menu, scrolling over to "System Settings" and finally down to "System Information". You should see your selected downgraded firmware is installed as the current "System Software".