PS3 how can I downgrade CFW 4.9 to CFW 4.8 or CFW 3.55?

[Poseidonhkg]

I got an PS3 with OFW 4.9 and jailbreak it with CFW 4.9 already, I would downgrade it to CFW 4.8 but unable to search / pick any tools to make it downgrade...

Is anyone can guide me please

 

[aldostools]

Enable QA flags. Once they are enabled, you should be able to install any supported FW version (higher or lower)

If you installed Evilnat 4.90, the option is found in Network > Custom Firmware Tools

 

[Poseidonhkg]

Enable QA flags. Once they are enabled, you should be able to install any supported FW version (higher or lower)

If you installed Evilnat 4.90, the option is found in Network > Custom Firmware Tools

Would you tell me more please? which QA tools I should use... ?

 

[db260179]

Would you tell me more please? which QA tools I should use... ?

Install the Evilnat 4.90 CFW firmware first then goto the Network/Custom firmware tools section in the XMB - Turn on the QA flags

The tools are built in to the evilnat firmware, so just do as specified.