(1) Go to Desktop-System and Security-System Update-Menu Key-Select Installation Package;

(2) Select the installation package consistent with the system version, and immediately update and restart the mobile phone.

Generally, as long as it comes with the mobile phone system, you can't delete the application. If you accidentally delete the application icon on the desktop, you can find the corresponding program in the settings, just open it directly, and then shut down and restart it. If not, you can directly restore the factory settings, and then open it, so that you can find the application software.