Newb Help - 3.03 OE-C to 3.90M33

[AzureDrake]

I've been gone from the PSP world for quite some time, deploying to Afghanistan soon so was looking to get it a new firmware installed. I currently have 3.03 OE-C installed and was trying to figure out a way to turn it into the newest M33 firmware. I tried once before, but I had lots problems re-upgrading the firmware past a certain version due to the keys. Any help is appreciated. =)

[AdamRav]

This should help ya

Using Chilly Willy's Key Cleaner it is possible to
Discover the exact motherboard type
Discover broken keys
And restore those broken key(s) on downgraded psp's.
After which it wold be possible to run any official firmware again... if you really wanted too.

http://www.fullburn.com/random/Clean_TA82_keys.zip

EDIT: If you don't already know

The latest custom firmware is 3.90 M33-2

[AzureDrake]

Would it be necissary to run the keycleaner to upgrade to a custom firmware?

I think at the time I was trying to go back to official, but now I plan on going M33. I looked around and it looks like ill have to take several different installs to finally get back up to 3.90, just trying to figure out the steps to do just that. Something about using the 3.03 oe-c recovery to a higher custom, then so on.

[jxx2005]

upgrade to 3.52 M33.3
then you can goto 3.90 m33