Connect your phone to a PC and follow these steps:-
Turn off your Samsung Galaxy phone
You can do this by holding the power button until the options pop up on your display
Choose turn off and let your phone switch off completely
Now hold the volume up and the Bixby button on your phone
While still holding them, press and hold the power button as well
After the logo is displayed, you will see the message Installing System Update on your display for up to 60 seconds
Allow your phone to process the files until Android finally boots up in Recovery/ Safe mode
You can navigate inside this menu only using the volume up and volume down buttons
Keep pressing the button until the highlight marker reaches wipe cache partition
Press the power key to confirm your action
Click on volume keys once again to select yes and use power key to confirm it
Let the process be complete after which you can choose reboot system now and wait for the phone to restart to the home screen
Wait for the Android logo to be displayed on your phone and immediately release all three buttons
RETIRED