Allright for those that want to turn a regular battery into a Pandora's battery read this thread.
http://forum.pspdiscussions.com/showthread.php?t=3195 - credit to Alex1337
It shows step by step how to do it. Note that it requires you to physically open a battery and cut one of the pins. You can turn it back into a regular battery (don't know why you would, just buy a new 3600mAh battery) but it requires some steady-handed soldering.
Link also has a GUI for Pandora which you will need.

As far as putting a CFW on your MS, which is required to downgrade your PSP check out this thread.
http://forum.pspdiscussions.com/showthread.php?t=3275 -credit to madpatriot55
and go to post #5 for my tut on how to do it. It also has links for 3.71 M33 CFW. There is also a link on there for HELLCAT'S Pandora Creator but that requires you to already have a CFW on your PSP.

Whoever asked about a 1 GB MS working, yeah it will work. MS has to be at least 256 MB and not more than 4 GB just make sure its a genuine pro-duo stick. But I'm not really sure what you were asking.