How to Downgrade PSP GO or PSP 6.39 to 6.20 Official Firmware

Read this for the sake of success:
How to install custom firmware on PSP GO and PSP 6.60, 6.39, 6.35, 6.20 : • Video
You are most likely doing this so that you can play ISO's on your PSP using 6.20 official firmware. To do so, watch this video after you are done with the downgrading video, How to play ISOs on your PSP or PSP GO 6.35 or 6.20 official firmwares:
• How to play ISOs/CSOs ...
If you are getting an error message (updater MD5 Mismatch), delete the 6.20 OFW update in the PSP - GAME - UPDATE folder and replace it with a 6.35 OFW update. This will make you downgrade your PSP to 6.35. 6.35 OFW is supported by the ISO hack. Watch how to play ISO's on 6.20 or 6.35 ofw in the video link above.
Link for PSP 6.35 OFW Update:
www.consolespot...
Link for PSP GO Downgrader:
www.mediafire.c...
Link for PSP 1000,2000,3000 Downgrader:
www.mediafire.c...
Link for PSP GO official firmeware 6.39:
www.mediafire.c...
Link for PSP 1000,2000,3000 official firmware 6.39:
www.mediafire.c...
COMMENTATOR TIPS:
From UA-cam User "markybhoyuk": If anyone's trying this and downloaded the psp go downgrader link, the psp/game/update/eboot.pbp is corrupt, you need to replace it with the offical psp 6.20 go eboot.pbp, thats why there is the md5 error, once you replace it, works fine.
FAQ:
Q1: The downgrader says my firmware is not supported!! What do I do?
A: If your psp has firmware over 6.39, then this downgrader will not work for you. If you PSP has firmware that is lower than 6.39, but is not working, upgrade to official firmware 6.39 (located in the links above) by putting the game folder into the PSP folder on your psp and updating it from system storage via the game section on the xmb.
Q2: My psp is higher than the firmware 6.39, what do I do?
A: Sorry, this video is not for downgrading any psp's higher than 6.39. I'll be making a video on downgrading firmwares higher than 6.39 soon so subscribe!
Q3: Why should I downgrade my PSP?
A: So you can use my video: • How to play ISOs/CSOs ...
or installing custom firmware for it • Video
Q4:Thanks, you are awesome, how can I help you?
A: My videos are very easy to understand and I will answer your comments if need be. :D My videos are also never going to be scams or have stupid little surveys. I just ask you to do 2 things for me, Sub if you will please and click on the ads in my video if you will please.