You are not satisfied with the functionality of the stock firmware.
Where can I find the firmware?
On the official Internet resource of the phone manufacturer.
On sites where third-party developers and phone manufacturers post custom or official OS.
What should be done before installing the firmware?
Create a backup copy of user data and transfer it to another medium.
Insert SD card. An SD card is needed to write firmware to it.
Remember your smartphone model.
Charge your phone fully.
Find and download the archive with Firmware. Place it on the SD card.
Installing TWRP Recovery
Download the Official TWRP App from the Play Market. Download, install and launch the application..
When you start the application for the first time, you must agree to install the firmware, as well as agree to grant the application Superuser rights and click the 'OK' button.
After moving to the next screen, select the 'TWRP FLASH' item and provide the application with root rights.
On the main screen of the application, the 'Select Device' drop-down list is available, in which you need to find and select the device model for installing the recovery.
After selecting the phone, the application will redirect the user to a web page to download the modified recovery environment image file. Download the proposed *.img file.
After downloading the image file, go to the main screen of the Official TWRP App and press the 'Select a file to flash' button. Then we tell the program the path where the file loaded in the previous step is located.
Press the 'FLASH TO RECOVERY' button and confirm that you are ready to start the procedure - press 'OK' in the question window.
When the message 'Flash Completed Succsessfuly!' appears. Click 'OK'. The TWRP installation procedure is now complete.
Copy the firmware and other necessary files to the SD card.
Insert a memory card into the device.
To reboot in recovery, it is convenient to use a special item in the Official TWRP App menu, accessible by pressing the button with three stripes in the upper left corner of the main screen of the application. We open the menu, select the 'Reboot' item, and then tap on the 'REBOOT RECOVERY' button. The phone will reboot into the recovery environment automatically.
Firmware via TWRP
Before flashing, you need to delete all user data from the phone, this will avoid many problems. press 'WIPE' on the home screen.
Everything is ready to start flashing. Press the 'Install' button.
The file selection screen appears. At the very top is the 'Storage' button, select the location where the firmware file is located.
Select the location where the files were copied. Press the OK button.
Find the file we need and click on it. A screen opens with a warning about possible negative consequences, as well as the item 'Zip signature verification'. This item should be checked by placing a cross in the check-box, which will avoid using damaged files when writing to the phone's memory sections.
The procedure for flashing the phone will begin, accompanied by the appearance of inscriptions in the log field and the movement of the progress bar.
The completion of the installation procedure is indicated by the inscription 'Successful'.