My i9190 is locked to the carrier called Personal and its CSC is PSN (the region is Argentina). I wanted to upgrade to kitkat, but I waited too long and the update is not coming. I recently rooted my phone, and wanted to flash a stock 4.4.2 firmware. I was thinking of this one: http://www.sammobile.com/firmwares/download/34383/I9190UBUCNG1_I9190UUBCNG1_ARO.zip/ My phone's stock firmware is this one: http://www.sammobile.com/firmwares/download/24122/I9190UBUBMK2_I9190PSNBMK1_PSN.zip/ How can I update my phone? Do I also have to unlock it? I already backed up my efs folder just in case.