i have a tmobile branded 8100 unlocked and i have cingular

i would like to add the cingular/or att theme to it
and have the push to talk software added as well

how do i do it

with desktop Manager

But how i can make active the PTT function, i'm from peru, the service is active, but my pearl don't have the option.... Claro Peru says that the service is only limited to motorola :s

somebody knows haw can i activate the PTT????

Thank you so much