what do you meen cover? like making a button and paste that over the switch? in that case you should cut some pieces of wood/plastic in the shape you want, if you use wood, take a soldering iron and 'write' the symbols, else you could take some kind of paint and paint the buttons with that, or take a clear piece of plastic, cut the buttons out in the shape you want them, and write the symbols on a simularly shaped piece of paper. the style can be whatever you want, i'd suggest you take a gba/psp like style, as that is easier. what do you meen with x and y?