No permission to Modify Jetcam files for Jetpack 4.5.1

Hi all,
I am following the jetracer git to build the autonomous RC car. However, my camera image is flipped and I found couple of solutions from internet, which all requires to modify the file. but seems I have no permission to modify the files in the /jetcam/build/lib/.
The jetpack log in password is “Jetson” . I wonder if there is any way I can modify the file and save it?

Thank you.
the jetracer git link is: jetracer/docs/ at master · NVIDIA-AI-IOT/jetracer · GitHub

You should be able to run sudo su to enter root user and modify any file. And please execute cmod 755 to the file and try again.