✔ 最佳答案
首先一定做左backup先, 不知道會否洗機.
region TGY就係港版stock rom,你用以上放法unroot係最徹底既
就咁用kies或OTA升級我唔sure有冇手尾跟,
你可以選擇唔跟片入面wipe(Volume Up + Home + Power buttons)
就咁刷rom咁你原本d data同setting應該係返哂到
但最好就wipe洗晒d野最乾淨啦(記得做backup先)
http://samsung-updates.com/device/?id=GT-I9300
unroot steps (English only)
http://www.jayceooi.com/2012/06/14/how-to-restore-stock-firmware-on-samsung-galaxy-s3-video/