How to Hack a PSP Slim Version 5.50 to get Custom Firmware?

I asked this question before but I didn't get a good answer. I need step by step guides and download sources. I also need info on the magic memory stick and pandora battery thing. If there's a way i can have permanent custom firmware without them that would be great but if not please tell me how to make a mms and pandora. Please tell me how to make a Pandora without cutting into my battery? If thats the only way then tell me how to do that too. Ty im a noob to this so help me plz.