I have a question about Custom Firmware

I have a Psp slim and Im worried I'll mess something up when I hack the battery. I want to know if there is a safer way to hack my psp without opening the battery.

Also, when using custom firmware will I have to use umds to use my gamesaves?

See, I'm hacking my PSP because I broke the UMD door.
Also want iPSP

you can purchase a pandora's battery and magic memory stick on an online store

Get a friend with an already Homebrew able psp and ask him to install Custom firmware in yours

opening the battery is kinda risky

no you wont need to use umds