First quarterly update.zip (with September security patch) for all CSC from CSC-OXM (Multi-CSC).
Update.zip from G950FXXU9DTF1 to G950FXXSADTI1 for SD card - https://mega.nz/file/dMxVlAKA#uTPB6-X6Agx5OC_3bNR6jzXwsiEN41KQ1DEQoOQJMdU
Changes - September security patch and new (A) version of bootloader.
New update.zip (with April security patch) for all CSC from CSC-OXM (Multi-CSC).
Update.zip from G950FXXSBDUA3 to G950FXXUCDUD1 for SD card - Mega
Changes - April security patch and new (C) version of bootloader.
You have to be on CRL3 (latest Oreo for BTU) to install the beta. Not CRLB, not CRLI, not ABCD, but CRL3. NO OTHER FW WILL UPDATE. Dual Sim variant owners can use this update as well.
NOTE: You can't go directly from CRL3 to the latest update, you have to start with ZSA5 and apply them one by one.
Step 2 Download and unzip the provided firmware. You should have 5 files in the folder
Step 3 Open Odin, and browse the files to their respective places. CSC: If you want to keep your data, select the HOME_CSC file, if you want a fresh installation, go with the regular CSC
Step 4 Power off your phone, then hold Volume Down + Bixby + Power. Once you see the warning screen, you can let go. Press Volume Up to enter download mode.
Step 5 Connect your phone to the PC and press Start in Odin. Once its finished, it'll automatically restart the phone.
Applying the Update
SD card method
Download the necessary update.zip(s) for your device according to your current software version.
Step 1 Copy the update.zip file to your SD card.
Step 2 Reboot the device into Recovery mode. (Turn off the phone, then Vol Up + Bixby + Power button)
Step 3 Go to apply update from SD card.
Step 4 Install the update, and be patient.
ADB Sideloading (ADB seems to be broken, no solutions yet.)
Download the necessary update.zip(s) for your device according to your current software version.
Step 1 Download the latest ADB ZIP file (Windows), then extract it to C:\adb
Step 3 Copy the update.zip file to C:\adb (or wherever your adb.exe file is)
Step 4 Put your phone in recovery mode and select Apply update from ADB, then connect it to your PC
Step 5 Wait until your PC installs the drivers, if you're doing this for the first time.
Step 6 Open command prompt, navigate to C:\adb (or wherever your adb.exe and update.zip is)
Step 7 Issue the following command: adb devices
If you can see a device in 'sideload' mode, you can proceed to step 8, otherwise you may have some troubleshooting to do.
Step 8 Issue the following command: adb sideload update.zip
Step 9 Be patient, and enjoy your update.
NOTE: You can't go directly from CRL3 to the latest update, you have to start with ZSA5 and apply them one by one.
IT IS STRONGLY RECOMMENDED TO PERFORM A FACTORY RESET IF YOU'RE UPDATING FROM CRL3. Otherwise its not necessary, but for
the most optimal experience, it is advised.