How to Flash Samsung Stock ROM:
Note: Keep in mind that prior to flash check out the battery time. It should be 70-80% charged. Backup your device data including personal data before flashing or installing firmware on your device.
Step 1: Download Stock ROM Firmware zip file in your PC and extract it.
Step 2: Download Samsung USB Drivers in install in PC. If already installed quit this step.
Step 3: Download ODIN v3.10.7, Extract it and then open / Run Odin.
Step 4: Now Press Button Home+ Power + Volume Button at same time for to restart the device in Download Mode.
Step 5: Now plug in your Samsung device with PC via Data cable and wait few minutes until blue sign in ODIN appears..
Step 6: Now its time to add particular firmware flash file in Odin using AP/PDA button.
Step 7: Prior to go ahead for start flash, check out re-partition option. It should not be marked / Ticked. If it is market please unmark it. Now proceed to Flash by click start button.
Step 8: Wait few moment until the flash procedure completed and you get notified for successful procedure completion. That’s it.
Samsung Galaxy S8 Plus Duos SM-G955FD