Is it possible to change the branding of the k770i, not debrand it?

Hi there, I am getting a second hand k770i sometime next week. I think it could be Vodafone firmware. Is it possible to change the branding to Vodacom South Africa? I think it's known as RSA-Vodacom. I am more familiar with the Vodacom firmware, and I quite like it. I knew it was possible, and I did it on the w910i phone I owned, before it died. Is it possible to rebrand it, and how? The method I did last time on my w910, was I changed the Cusomize_Upgrade.xml, and then I ran a Sony offical upgrade and that changed the firmware for me. Is it possible to do the same on the k770i, and how? Can I pleae have detailed instructions, and links, becuase I don't want to bugger anything up.

Thanks

Paul