I apologize if this does not seem directly related to ROS but I am ultimately using this for ROS.

I have a URDF file of a robot that I created. I have also found a velodyne lidar simulator here: https://bitbucket.org/DataspeedInc/velodyne_simulator/src/master/

My question is: How do I use this simulator in/on the URDF file that I have for my robot? Is there a special way to link 2 URDF files together? I am VERY new to all of this. I would appreciate if you could keep the answers as simple as possible so that my tiny brain can understand lol. Thank you.