Generally, changing CSC in android phone is a grueling process. You must root it, install TWRP custom recovery and then flash files necessary to change CSC. However, there is a way to change CSC in Samsung Galaxy Note 9 without even rooting it.
Before you proceed, you need to have Samsung USB drivers installed. You’ll also need the original USB cable.
Download your combination file from here.
Download your new CSC firmware from here.
Download Samsung Odin 3.13.1 from here.
Download RealTerm from here.
Fire up ODIN, click AT and select combination file. Put your Galaxy note 9 in download mode by turning it off, then holding down volume down and bixby buttons while inserting USB cable. Confirm that you really want to enter the Download mode on your Galaxy Note 9. Click on Start button.
Now, open RealTerm > Port tab > Set Baud to 230400 > Port to ssudmdm0000 or very similar name.
Now, move to send tab and enter "AT" and click Send ASCII.
Now, enter "AT+PRECONFG=1,0" and click Send ASCII.
You will get this response.
AT+PRECONFIG=1,0+PRECONFG:1,???
OK
-??? is your current CSC.-
Enter "AT+PRECONFG=1,0" and click Send ASCII.
You will get this response.
AT+PRECONFIG=1,0+PRECONFG:1,???
OK
-??? is your changed, current CSC.-
CSC change is now complete.
Now, turn off your Galaxy Note 9 and put it again into Download mode. Fire up, ODIN again and fill each fied – BL, AP, CP and CSC – respective files from the firmware which has the new CSC.
Use the CSC file in the CSC field, not HOME_CSC.
Click start. This will now wipe your phone completely.
That is it. You’ve successfully changed CSC in Galaxy Note 9 without rooting.