How Do i Flash My 6800 to alltels rom?

[Jrod7410]

I have a Spring 6800 smart phone that's flashed for metro service. it has the original sprint rom. i would like to change the rom to alltels rom, Cause some one told me that its faster and it works better. Also i don't want it to mess up my metro settings when i flash it over to alltels rom. in case you where wandering I have try ed and i have not been successful in doing so. I'm new to this form and any help would be appreciated. thanks.