Hi @tencyyawan26, let me see if I can help out here!
Could you possibly elaborate your question a bit? If I understand your question correctly, you wish to reset the phone to the condition it was when it was brand new software wise. There is basically two ways to do this. The first is to do a factory reset using the settings of the phone (Settings > System > Advanced > Reset options > Erase all data) the other is to do a software repair using Xperia Companion and a computer.
I hope that helped, please do elaborate your question if I have misinterpreted your question in any way!
