Get a brass wheel collar that just fits over the end of the glow plug (make sure it is brass and not aluminum), solder a wire to it to connect to your ignitor battery. Place a small insulator (a thin slice of silicon fuel tubing) between the head of the motor and the wheel collar when you put the collor over the plug. Connect the other end of the battery to any part of the motor block through an appropriate length of wire. Mount the two wires going to the battery anywhere convenient for acess.