How to Flash Samsung SM-A300F:
Make sure your device is at least 30 percent charged to perform flashing.
• Switch off the mobile
• Press the Power + volume UP. Phone will enter in Recovery mode then select Reboot to Bootloader by pressing Power Key.
• Phone will turn into Download Mode.
• Now open the Odin flash tool and follow the steps as shown in the video
• Select Samsung SM-A300F
• Select the Odin tool and open it
• Select BL file
• Click AP or PDA then select AP File
• Click CP and select Modem File.
• Click CSC and select CSC File.
• After selection mobile will get detected automatically
• Now click start on system & installation is in process
• After installation mobile switch ON of its own.