Things You'll Need
Instructions
Turn on your PSP and navigate to the "Recovery" folder.
Select Hellcat's Recovery Flasher v1.60.
Select "I Agree" after thoroughly reading the warning screen.
Select the Custom Firmware currently installed on your PSP.
Select "Backup Flash Content."
Select "Create Backup Flash0/1." This will back up your NAND file. You can also restore the NAND file from the same menu.
Press the triangle button until you reach the main menu.
Select "Install M33 CFW."
Select one of the reset settings. Wait for the reset to complete, then restart your PSP.