Step 1. USB storage device, such as a USB flash drive. There must be approximately 460 MB of free space.
Step 2. On the USB storage device, create folders for saving the update file. Using a computer, create a folder named "PS4". Inside that folder, create another folder named "UPDATE".
Step 3. Download the update file, and save it in the "UPDATE" folder you created in step 2. Save the file with the file name "PS4UPDATE.PUP".
Step 4. Access to and use of the PS4 system software update are subject to your acceptance. Connect the USB storage device to your PS4 system, and then from the function screen, select (Settings) > [System Software Update].
Step 5. Follow the on-screen instructions to complete the update.
Step 6. If your PS4 system does not recognize the update file, check that the folder names and file name are correct. Enter the folder names and file name characters using uppercase letters.

Do not downgrade.