If you run Windows and are able to/don't have issue with modifying the registry;
Windows Registry Editor Version 5.00
[HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Keyboard Layout]
"Scancode Map"=hex:00,00,00,00,00,00,00,00,03,00,00,00,1d,00,3a,00,3a,00,1d,00,00,00,00,00
Copy the above text to a word document, save the document and rename it from "whatever.txt" to "whatever.REG". When you run the file it will swap Ctrl with Caps Lock. If you want to change back to default simply go to the specified location in the windows registry editor [HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Keyboard Layout] and remove "Scancode Map".
Had to do some digging to find this kind of stuff for myself, but I edited it so that my Caps Lock registered as Shift because I get a bit clumsy with my pinky when gaming (it also makes it easier to hit shift+5/6).