hi I need help upgrading my psp its been a longtime since i did my last upgrade on my psp it is hack cuz i remember that i did it is now on a 4.01 m33-2 and i did tha pandora battery witch means that i have PSP-1001 i dont now what is the best upgrade to put on and how to do it like i said its been more than 2 years since i did the last update i will appreciate anyone that offers to help me

thank you