You can view and/or download the file/s from the Digital Files area.
If you want to to make any edits to the model or toolpaths, import the design into Fusion 360 and made edits as necessary to the model or toolpaths. Make sure to re-simulate toolpaths after edits are made and export the gdode local to your computer.
For this step the folks at Inventables have made it about as easy as they can to bring in g-code from external sources. I don’t think its turned on for everybody just yet but there will be an option under the File pulldown to “Import g-code”. If you want this option and don’t have it, you can ask for it it on the forms and they typically turn it on for you in a day or two (now that service).
You can then import the attached file into a new project and and cut right from Easel.
Carve left side of organizer after importing in g-code. Once it has carved slots for the left controllers, unclamp the stock and slide it half way down to be able to carve the right side as well. I have taken pretty small steps so total time for this is likely to be around 4 hours.
Lightly sand the slots and top of the organizer. To add a nice touch to it you can nail on some trim around the outside of the organizer to give it a little lip. Put on a nice coat or two of paint and stick a few felt pads on the base to make sure it doesn’t scratch whatever surface you put it on.