If you're lucky enough to have a mill that can create the whole disc in one go use the file ending "...(Full).nc". This mills the whole disc in one go. Unfortunely my mill can only do about 8cm x 16cm, so I also split the gcode in two. The file "...(Part 1 of 2).nc" and "...(Part 2 of 2).nc" are for those of us will smaller mills! You need to mill the first, rotate the workpiece 180 degrees and mill the second.
An hour or two later, you will end up with a finished physical disc that you can pop on your record player and see how it sounds. Here's how mine turned out:
and I've also managed the Star Wars theme
and if you want to see the process in action, here's a thankfully short clip of it being milled