The proper way of remapping /cmd_vel?

Hi, right now, I have remapped the /cmd_vel topic into another name (basically the same name but with an extra prefix). The way I did this was to edit /opt/ros/noetic/share/magni_bringup/launch/core_launch.em . However, I was wondering if there was a better way of doing this? I’m worried that if that package gets updated via apt in the future, those changes would get overwritten.