Place theme.p3t file in X:/PSP/THEME/ folder and select theme from XMB->Settings->Themes
X is your psp USB or PSP media card
Or Download Only theme file directly from your PSP internet browser.
Description:
My first Theme for Psp (august,22,2008)
i just learned about this theme stuff yesterday.. and i watch alot of vids about it.. so i wanted to try it out.. this is my Very First Theme.. i might get bad comments on it, but it takes alot of time and thinking, (so ya.. if u want me to update it more just tell me)
NinjaGaiden_2 
Stewie Most Wanted
PSPMMO Theme
