PSP developer some1 has updated his 6.38 Downgrader to support 6.39 OFW. If you’re not familiar with this PSP jargon, it simply means that using the 6.3x to 6.20 OFW PSP Downgrader to downgrade a PSP from the latest official firmware (6.39 OFW) to 6.20 OFW.

Simply visit my updated 6.3x to 6.20 OFW PSP Downgrade guide for more information.

Credits go to:
some1 for the 6.3x to 6.20 OFW PSP Downgrader
Davee for the initial downgrader release