Homebrew developer PHPnerd, StiffMeister & Lewishamilton from http://www.psp-hacks.nl come with an update from their own Easy Installer!

With this Easy Installer you have to choose if you have a PSP Fat or Slim & Lite and if you want 1.50 kernel or not! Iit copys all the files needed for the upgrate to 3.90 M33 at once to your PSP! Verry handy for people that are lazy or can’t get along with a PSP but still want to enjoy 3.90 M33.

Thanks to Sebastiano for the news.