Follow the on-screen instructions. Your PSP will reboot, now running Official 6.60 Firmware. Step 2: Install 6.60 PRO-C2 Custom Firmware Once you are on 6.60, you can reinstall custom firmware. Download the package.
: If you encounter errors, use Key Cleaner by Chili Willy to repair "bad keys" that often conflict with older custom firmwares. Step 2: Installing Official Firmware (OFW) 6.60 psp 352 m33 upgrade to 660
Safely disconnect the USB session. On your PSP, navigate to Game > Memory Stick and launch the . Follow the on-screen instructions