The light blue labeled circles indicate connection points on the MX, and also on the consoles main circuit board (underside), connect an insulated wire from MX upgrades connection point to the relevant point on the board. Kynar wire is recommended (38swg) for all connections except 'A' and 'C', these should use 1mm insulated wire. The MX upgrade should be affixed to the circuit board using a sticky-pad.
Please note that MX is manufactured as an 11-wire design, therefore it is not necessary to connect point 'B'.