Default ___???___How Moto G XT1034 to GPE (need AWS) ???

…..I tried , I don’t know how ….
I know to convert my Moto G XT1034 to GPE ( I did it once) but I loose signal …. Need AWS signal (T Mobile)
Somebody has a guide how to do it ?
Please help ….. My wife has a NEXUS 5 , I would like to be MY MOTO G the same ….almost ….but need AWS radio signal ....