You are not satisfied with the possibilities of the stock firmware.
Where can I find the firmware?
On the official website of the manufacturer.
On sites where third-party developers and phone manufacturers post custom or official OS.
What should be done before installing the firmware?
Back up your contacts and user data and transfer it to your computer.
Insert an SD card into your phone to write the firmware to it.
Determine your smartphone model.
Charge your phone fully. If the battery runs out during boot, the device will no longer turn on. It will be difficult to restore it.
Find and download the archive with Firmware. Place it on the SD card.
Installing TWRP Recovery
Download the Official TWRP App to your phone from the Play Market. And install this app.
When you start the application for the first time, you must consent to future manipulations, as well as consent to granting the application Superuser rights. Check the checkboxes and press the 'OK' button.
In the next screen, select the item 'TWRP FLASH' and provide the application with root-rights.
On the main screen of the application, click 'Select Device', and select your phone model.
After selecting the phone, the program will redirect the user to a web page to download the corresponding image file of the modified recovery environment. 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 your choice, press 'OK'.
After the burn process is complete, the message 'Flash Completed Succsessfuly!' appears. Click 'OK'. The TWRP installation procedure can be considered complete..
Copy the firmware and other necessary files to the SD card.
Insert a SD memory card into the phone.
To reboot into recovery, you need to enter the menu accessible by pressing the button with three stripes in the upper left corner of the main screen of the application. Select 'Reboot' and then click on the 'REBOOT RECOVERY' button.
Firmware via TWRP
Before flashing, you need to clear the 'Cache' and 'Data' sections, press 'WIPE' on the main screen. You will delete all user data from the phone, this will avoid software errors and other problems.
You can start flashing. Click the 'Install' button.
The file selection screen is displayed. At the very top is the 'Storage' button, which allows you to switch between types of memory.
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, you need to check the item 'Zip signature verification', which will avoid using corrupted files when writing to the phone's memory sections.
The procedure for writing files to the phone's memory will begin, this is accompanied by the appearance of inscriptions in the log field and the movement of the progress bar.
After the firmware installation procedure is completed, the 'Successful' message appears on the screen.