Xt1055 4.4.4 Stock ROM + Unlock Proceedure needed !!!

i heen seen XT1055 working on GSM network .. but i don't know how they are working .. after OTA , network will be gone ..

so i have to repair those phones ... i have failed so far .. i have tried every attempt but failed ..

anyone know how to unlock XT1055 ....

i also need XT1055 4.4.4