Demonstration model: Iphone 1 1 System version: iOS1313.3.1Capable. However, because the gray part of iphone memory is mostly other memory with application cache class, it cannot be completely deleted. You can delete a part by cleaning the application cache of the mobile phone.
This graphic tutorial is made by iphone 1 1 and system ios 13.3. 1
1. Unlock the phone, find the settings, and click Enter.
2. Then enter GM.
3. Slide the phone down to see the storage space of iPhone, and click Enter.
4. Delete the software or files belonging to the gray space.