Here's the 3.03 upgrade EBOOT: http://www.psp-hacks.com/file/958
3.03 downgrader: http://rapidshare.com/files/15133909...Downgrader.zip
3.10 OE-A: http://rapidshare.com/files/14886208/3.10oe-A.zip

Upgrade to 3.03 first, run the 3.03 downgrader (there's an included readme,) then upgrade to 3.10 OE-A and have fun.