Hi there,
I have just finished writing my tutorial on upgrading to the latest 3.71M33 firmware, and it is available here:
PSP Custom Firmware 3.71 M33 Guide | Karol Krizka
It includes the following:
- Step By Step Instructions
- All Needed files
- Instructions for 3.71 M33 Upgrade
- Instructions for adding 1.50 kernel support
- Instructions for installing the Custom Firmware Extender 1.6