I would like my Microsoft/nokia Lumia 640 that runs on Metro Pcs to be flashed to the T-mobile ROM, Does anybody have a step by step instuctions on how to perform this? I have read about flashing the ATT version here lately(looks complicated)I thought it would be simpler to flash T-mobiie on to Metro Pcs since they run on the same network.Would gain wifi calling and better plans with t-mobile. My metro pcs 640 runs windows 10 and is not unlocked, would the flashing also enable me to use T-mobile without having to get an SIM unlock code? thanks folks!