ok first you install the patapon 2 demo.
then you download the half byte loader from here (the higher the rev number the newer it is)
http://wololo.net/wagic/hbl/afterwards extract everything to your psps root, you know the first place you get when you go on to your memory card.
now you download the save game exploit file from the same link it says patapon exploit
download that and extract it to psp/savedata. youre done installing
then install all of your homebrew the way you would usually do
then on your psp start up the demo, load the hacked save file and once it loads
PRESS R
now select your homebrew and have fun...
hope this helps.