How do I repaint furniture?
Remove the doors and all hardware, if you can remove the glass that is even better; if not just mask the glass.  Take a fine grit sandpaper like 320 and sand everything that is black to scuff up the finish (you don't want to paint on a finish).  Get a few cans of white spray paint in whatever finish you want and start spaying.  In multiple light coats allowing time to dry between coats and in a well ventilated area.  Most paints nowadays spays included shouldn't need a primer.