How do i update my PSP from 5.00 M33 to the latest cfw?

I just downloaded Smack down Vs Raw 2011 and its not working on my PSP. I'm assuming this is because i need to update my cfw. i am currently running 5.00 M33. I cant seem to find another M33 update, so which update do i need to get to run Smack down Vs Raw 2011 and how do i install it over my current version (5.00 M33)?