PSP "Pandora's Battery Frim. Installer Wont start"

I want to make my psp slim 3.6 to a psp slim 3.6m33 and to do that i have to have "magic memory card" and pandora battery and when i try
i cant start Pandora's Battery Frim. Installer
When i press on the icon and the psp start thing comes (the yellow thing with a white background) and then after 10-15 sec it shuts down :roll:
I did everything according to guides (i read a lot of guides)

I have firmware 2.8 on my psp "fat"
and firmware 3.6 on my "slim"

PLEASE ANWSER ME QUICK PLEASE!

You cannot run homebrew on firmware 2.80. You need to have either a custom firmware or 1.50.

But how do i make a CFW?