Refer to the wiki page.
Install following ROS packages in your catkin workspace:
roslaunch map_server gmapping.launch
Push CaBot slowly down desired mapping route (should see map start to form in rviz)
After you've reached the end of the mapped route, run:
rosrun map_server map_saver -f desired_map_name
This command will save a .pgm and .yaml file of your map that can be used on the navigation stack.
You can also use hector_slam instead of gmapping. To do so, run
roslaunch lidar_map urg_lidar.launch
roslaunch lidar_map build_map.launch
This package's mapping part is directly copied from demo, thus containing many confusing and inaccurate parts in the configurations and launch files.