You could load the lib.so into IDA Pro and find the functions leading to the check where the root is being detected. Then hook it the function to return the value. If you're not hooking, but want to edit it the lib in IDA itself, you need to hex patch it. If it's a small check, I think there is a tutorial on here on how to bypass it.
You can't delete a file that is part of the games files, if you do, it will either crash or will never start up. You can delete one architecture of ARMV7 or arm64.