You need to know where your saves are located (usually in ~/.steam/steam/userdata/STEAM3 ID/218620/remote. or C:\Program Files (x86)\Steam\userdata\[STEAM3 ID]\218620\remote and make a note of the ID marked here as "STEAM3 ID". These scripts will fail if you merely try to run them first time without doing this setup. Add your STEAM3 ID to the marked places in the file, and then run it. Then hope and pray to Linus Torvalds and/or Bill Gates that nothing broke.

To use the Linux script:
Do as above, then run the .sh file via Terminal.

To use the Windows script:
Do as above, then double click on the .bat file and it'll run via command prompt automagically.