The bare requirements is that you need to have the last iteration of the M33 CFW and you can easily upgrade to this version.
Instructions: Copy UPDATE folder /PSP/GAME/ and run.
Put the 4.01 sony update as 401.PBP in same folder, or let the program download it for you using a wifi connection.
Changes:
- Bug fix: vshmenu didn't let change camera mode due to camera_plugin using select button.
Fixed, now vsh menu will not be loaded when using the camera.
- Recovery can now be translated, See how below. Translation to spanish is autoincluded.
- Updated the M33 SDK with a new function and sample, and released the psp-packer tool to
compress prx's and PBP's in the ~PSP format.
- The folder of 4.01 and higher homebrew will be GAME4XX so it won't need change on update.
Easy Installation
For a Worry-Free Installation, you should have 3.90m33-3 Custom Firmware first
1.Download the Needed Files, if you don't have Winrar, you should Download it HERE.
2.Extract only the Update Folder, Put it onto your Memory Stick.
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3.Rename the Sony Official Firmware to 4.01.PBP, Place it inside the UPDATE folder, otherwise the installation won't work.
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4.Exit the USB mode and run the update on Memory Stick>Game, it will take you to an official SONY updater and follow the simple procedures onscreen.
OPTIONAL: (this will prevent future troubles if there are incompatibilites with the new firmware from your old one.)
5.Rest Default Features on Settings>System Settings> Restore Default Settings within the XMB. Also format the memory stick (backup your Saved Data and Games first) on Settings>System Settings>Format Memory Stick.
You can get the custom firmware and the needed firmware here...
Download: 4.01 M33 and 4.01 Official Firmware (needed)
Sources:
Via QJ.Net, Playstation.Com