Errors constantly appear in the Android operating system.
Some installed applications stop opening.
Some programs from the Play Market do not start.
The phone restarts or shuts down by itself.
The phone is slow.
You are not satisfied with the functionality of the stock (official) firmware.
Where can I find the firmware?
On the phone manufacturer's website.
On specialized resources where users post custom or official OS.
What should be done before installing the firmware?
Create a backup copy of all personal information: contacts, photos and transfer it to another computer.
Insert your SD card into your phone. It must have enough memory to fit the firmware.
Determine your smartphone model.
Fully charge your phone. If the battery runs out during boot, the device will no longer turn on.
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.
Going to the next screen, select the item 'TWRP FLASH' and provide the application with root-rights.
On the main screen of the application, click on the 'Select Device' drop-down list, and select your phone model.
After selecting a device, the program redirects the user to a web page to download the corresponding image file of the modified recovery environment. Download the suggested *.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. Select the file downloaded in the previous step.
Now 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 required files to the SD card. Using a PC or laptop card reader, it will be much faster.
Insert a SD memory card into the phone.
To reboot into recovery, you need 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. Open the menu and select the 'Reboot' item, 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. This will delete all user data from the device, but avoid a wide range of software errors and other problems.
Now you can start flashing. Press the 'Install' button.
The file selection screen appears. At the very top there is a 'Storage' button for selecting an SD card.
Select the location where you copied the files..
Select the firmware file 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 damaged files during recording.
The procedure for writing files to the device's memory will begin, accompanied by the appearance of inscriptions in the log field and the completion of the progress bar.
After completing the installation procedure, a 'Successful' message appears on the screen.