3. If you are on firmware ending in AUI5 for the CSC version XAA then skip to step #6 . If you are not, then download the respective firmware HERE
Also Download Patched ODIN (Patched version will be less scrutinous) HERE
4. Unzip the firmware you just downloaded as well as the Patched Odin. Run ODIN and add the BL, AP, CP, Home_CSC from the unzipped firmware to the corresponding locations in ODIN
5. Turn off phone and boot into "Download Mode" by first holding Volume +/- buttons and then hold the Power button. Now plug in your phone to your PC and you will see the first small grey square in the upper left side of ODIN turn light blue (if it does not, you have issues with either the cable or drivers).
Proceed in flashing the device by simply clicking the "Start" button.
Once it is done and your phone has rebooted... Make sure that you complete the setup process just in case of authentication issues if the phone isn't already set up
7. Follow the XDA adb install guide and make sure to allow adb systemwide when asked by the program.
8. Turn off phone. Boot into device by holding Volume Up and then holding Power. This will take you into recovery mode, where you will see the option to "update via ADB sideload".
Use the volume down key to navigate down to that option and press power to initiate the adb sideload function
9. Open command prompt by pressing the Windows key and typing "cmd" (no quotes) and press ENTER.
10. Type into the command prompt (of course remove the quotes) "adb sideload C:\path\to\your\oneui4\zip\file" . For example if I download that file into my Downloads folder, I would then type "adb sideload C:\Users\MyPC\Downloads\949981470b3948c3aa05a19e8a2edbd3.zip"