1. Extract (unzip) the Samsung firmware file. Recommended using WinRAR or 7-Zip
2. Download Odin Tool 3.13.1
3. Extract Odin ZIP file
4. Open Odin execute file
5. Reboot Samsung phone in Download Mode (hold Home + Power + Volume Down buttons / hold Volume Down + Bixby buttons then plug-in cable)
6. Connect you Samsung phone and wait until you get a blue sign in Odin
7. Add the 1 file Samsung firmware to AP/PDA or 4 files Samsung firmware (AP/BL/CP/CSC) to it's slots
8. Make sure re-partition is NOT ticked
9. Click the START button, sit back and wait few minutes