This zip file contains 2 open sourced scripts; skp_to_dxf.rb and dxf2gcode.py. To install a .rb plugin for SketchUp, these instructions are useful: SketchUp Help. The python script comes with a folder of supporting files – just copy the whole folder to your computer and run the script by clicking dxf2gcode.py. This should work ‘out of the box’ on Apple machines.
Dxf2gcode is Copyright (C) 2010-2014, Christian Kohlöffel and Jean-Paul Schouwstra under the GNU license. Skp_to_dxf’s orginal authors are Nathan Bromham and Konrad Shroeder with extra code from git-hub sketchup-stl project under the Apache License, Version 2.0.
Download the .zip here: sketchup_to_laser_cutter.zip