The installation is complex, requiring a Pandora Battery and Pandora memory stick, a non-Slim PSP with firmware 1.50 or custom firmware that supports 1.50 kernel, and of course, a PSP-2000. As always, this is not for the faint of heart nor anyone who hates carefully reading and following instructions, as there is always a possibility of bricking your brand new PSP-2000. As such, use at your own risk. Full instructions for the installation can be found here.
Download M33's custom 3.60 firmware here (scroll down to the bottom of the first post).
[via DCEmu, thanks everyone who sent this in!]