Question [Q] Go back from Rogers GB to ATT Froyo

I updated from ATT firmware to Rogers V20C.
I don't like the update since it doesn't support Spanish, that I need to use for my wife.
Also, I wasn't able to make the FM radio work.
I want to go back to ATT original firmware
I tried 'Recovery Phone' in the LGMobile Support tool, but it tells me that this model can't be updated.
How can I go back to the original firmware?