Help Installing Downgrader for 2.6

I really need someone to help me cos i'm just a little unsure about how to use the downgrader right, i have all the file needed but i am not so sure as to where they go. I am a bit stuck cos i have two folders on my PSP one called MP_ROOT and
PSP now the readme file tells me to put the
DOWNDATER file into the root of my memory stick is that the folder called MP_ROOT or PSP. I really want to downgrade but i also want to do it right and not brick my psp that is why i am asking for your help. I really hope you can help me.

THANKS....

put the folder into your root, for example if your psp's letter is f, the folder should be f:\DOWNDATER
make sure your psp's 2.5 or 2.6. it isn't that ta-82 motherboard, fully charge it, plug in the ac adapter.
MAKE SURE THAT YOU HAVE THE 1.50 DUMP AND .PRXs, YOU CAN GET THEM FROM psp-hacks.com. they have a nice little package, it's about 10 megs. i tested it and it worked for me. also put the eboot into your psp\game\downdatertest\ folder. and there you go.