[Jachra]

@seferismo,

You can use the M33 creator and then upgrade with just M33-4. The M33 creator goes into /PSP/GAME150. In the M33 creator folder goes also the firmware 1.50 as 150.PBP and the firmware 3.52 as 352.PBP. Afterwards yo have to rename the GAME303 folder to GAME352.

The update M33-4 is a cumulative update. It has also the updates from M33-1, M33-2 and M33-3.

Good luck