Location of move_group_interface for UR5

Hi! I'm trying to control an UR5 via MoveIt! in Indigo on a Linux Ubuntu 14.04 system. I did all the tutorials of ROS and [Getting-Started with an UR5](http://wiki.ros.org/universal_robot/Tutorials/Getting%20Started%20with%20a%20Universal%20Robot%20and%20ROS-Industrial). And I do find the tutorial for [Move Group Interface/C++ API](http://docs.ros.org/hydro/api/pr2_moveit_tutorials/html/planning/src/doc/move_group_interface_tutorial.html). And there I understand the single points described. But I do not understand which file exactly I have to change here. Where can I find or where do I have to build this file? Is it somewhere in the catkin-workspace or somewhere in opt/ros/... Did I miss a tutorial at some point where this is described? Thanks in advance!