If you are looking for how to factory reset iPhone, you just need to follow the below steps:
Here is a detailed description of how to factory reset iPhone:
Simply before factory resetting iPhone, you should make sure you have saved your data and apps.
After that, you need to open your iPhone. In order to factory reset iPhone, click on Settings. Here you’ll find the General settings section; you need to click on it to proceed. From there, you will find the Transfer or Reset iPhone option. You need to tap Erase All Content and Settings.