1. Connect to your computer and update it with itunes on your computer.

2, mobile phone update, but delete some applications that take up a lot of space. Generally, photos and videos should be removed, and this is the biggest one. Other settings, general usage, dosage and views should be entered into the mobile phone.

3. Like the picture above, watching videos online takes up the largest space and can be uninstalled.

4. If necessary in the future, reinstall from the store after upgrading.