As far as I know, the kailh switches on your BW2014 is a clone of cherry switches. So, it means that the pins of genuine cherry browns (or any other cherry switch) can fit the holes on the pcb.
So, to do this, get a soldering iron, a soldapullt, some wick or even better, a desoldering station, some solder and some time.
Open up the Blackwidow. There are screws hidden under the feet at the bottom of the case. Use something to pop the small tabs that hold the top case and bottom case open.
Next, unscrew the pcb+plate thing from the bottom case. Detach wire. Desolder switches and solder in new ones. Put case together. You're done