how can i use a dcu 60 cable to unlock a w300

[buwuve]

If you only want to flash it (for free), you'll use XS++ and Far.
Unlocking isn't possible (Semc 8.4 don't support the w300) for free. With a normal DCU60, I would use DaVinci (cost 30 Euro) . If you have a service cable too, use TMS (it's cheaper - only 6 Euro, you get them here on topsony