Almost all mikes these days are low impedance and balanced, to connect it to a 1/4 inch jack plug you simply connect one of the two conductors to ground along with the screen. The 1/4 inch jack plug should be mono, not stereo, a stereo one connected like you suggested won't work in a mono socket.
However, as the mike is low impedance, and the guitar input high impedance, it won't work at all well - it will be very quiet. Easiest solution is a mike transformer, you can buy these for this exact purpose (either as an adaptor, or a short lead - I prefer the short lead versions) - it accepts a 600 ohm balanced input, and provides a 50,000 ohm (supposedly) un-balanced output. It still won't be very loud though, as a guitar is a high output device, and a mike a low output device - but it's 'near enough' and has been used that way for many decades.