How to "downgrade" a PS4: full tutorial by Modded Warfare - Wololo.net
Wololo sur Twitter : "@SElghezal @HackConsole @_m4rty06_ Downgrade is possible but you need to have the right stuff backed up from a previous version of the firmware installed on the same console,
How to Downgrade PS4 from 10.01 to 9.00 Tutorial + Download - YouTube
How to Downgrade PS4 from 10.01 to 9.00 Tutorial - YouTube
Reverting a PS4 from 10.01 to a Jailbreakable Firmware (Full Guide) - YouTube
How to "downgrade" a PS4: full tutorial by Modded Warfare - Wololo.net
How to downgrade PS4 9.50 Beta software to the previous version of the system software - YouTube