4.01M33 Upgrade Guide

1)Go to recovery mode and set your kernel to 3.XX (If you're on 3.52m33, then set it to 3.52 kernel) 

Recovery : Hold the off switch for about 3-4 seconds,then HOLD R and boot your psp up.You should be in recovery mode.Now go to configuration,and hit X at the third option (Game Folder Hombrew) until it says "371".

2)Then download http://exophase.com/files/psp/401M33.rar

3)Download this too http://exophase.com/files/psp/401.PBP

4)Now open the 4.01m33 installer (step 2), and you should see several files and folders including the UPDATE folder.

5)Copy the UPDATE folder and paste it in PSP/GAME.

6)Now,time for the 4.01 eboot 

7)Copy the 401.PBP and paste it in the UPDATE folder as well.

8)It should be like this ms0:/PSP/GAME/UPDATE/eboot.pbp and the 401.PBP

9)Execute the installer from the game tab.

10)After the installation finishes, REMEMBER TO CLICK X OR YOU'LL BRICK.

11)Done! Enjoy!