Changelog:
v3.5: If the 6.20 updater MD5 check fails, it will check if the update file is 6.35, allowing non 07g/09g to downgrade to 6.35, added source, removed a few debug printf's
This allows users who are incontent with their firmware to downgrade to 6.20 using the Sony Updater.
Copy the "PSP" folder to your PSP. The downgrader is "signed" and can be launched from OFW XMB. You need to copy the 6.20 update to PSP/GAME/UPDATE/EBOOT.PBP and for PSPgo it must be the eflash it is placed on. After setup run the downgrader and follow the onscreen instructions.