I'm trying to run snes9tyl on my psp. I've updated my PSP to 6.61 but I need to get it downgraded to 1.50

I found a tutorial on how to do so and it says I need Rain's Simple MMS maker. I've managed to find a working download of the "ultralite" version but it does not have the "firmware/EBOOT" pull-down menu which gives me the option to select "DCv4" as the tutorial instructs.

I've been looking for a working download of Rain's SIMPLE MMS maker (NOT Rain's UltraLite MMS Maker) and EVERY SINGLE LINK I'VE FOUND IS OUTDATED AND NO LONGER WORKS!!!

Can somebody please provide a working link to this application?