I need help with custom firmware

[EkansLidos]

Well I'm not really good with hacking my psp but i don't know where too get this file i'll just copy and paste the readme i don't know what the hell he's talking about this is what i need "3.52 M33-3 or higher. " My System Software Is Version 3.73


3.90 M33
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Requeriments:

- Installation requires a PSP with 3.52 M33-3 or higher.

Instructions

- Copy the UPDATE folder into /PSP/GAME/
- Get the 3.90 sony update from somewhere, and put it in same folder, with name "390.PBP".
Alternatively, you can let the installer to download for you via wifi.
- Run it, the update will be done by Sony updater. At the end when you are asked to reboot the
PSP pressing X or O, do it.


Changes:

- 3.80 -> 3.90
- March33 NO UMD: fixed (yet another) bug related with exiting with home. (infinite semaphore wait)


Changes in updater:

- The degeneration check and correction of IDS keys happens too in 3.71 now.
- Added code to download 3.90 PBP from net via wifi.
Note that his code is not yet 100% stable, it may crash when selecting AP. In that case,
reinit the installer.
- L+triangle has been restored as method to bypass battery.
If you already have 390.PBP keep those buttons pressed until you see "Veryfing 390.PBP".
If the 390.PBP is being downloaded bia wifi, press those buttons at the end of download until
you see the previous sentence.

[havoc802]

you need to downgrade to 1.50 with the pandora battery and t hen upgrade to custom firmware.