I RECENTLY DECIDED TO CHANGE THE DOUBLE LIGHT SWITCH ON OUR LANDING TO A DIMMER, HOWEVER INSTALLING IT AS TURNED OUT TO HARDER THAN I EXPECTED. THE SWITCH SHOW SERVE BOTH THE LANDING AND DOWN STAIRS IN THE HALLWAY. THE INSTRUCTION ARE RUBBISH AND I SEEM TO HAVE MORE WIRES IN MY WALL THAN THERE ARE IN THE DIAGRAM, I HAVE 1 EARTH WIRE, 2 RED WIRES AND 3 BLACK WIRES. ON THE DOUBLE DIMMER I PURCHASED, THERE IS A PLACE FOR SECURING THE EARTH WIRE AND 6 OTHER TERMINALS, 2 MARK C, 2 MARK L1 AND 2 MARKED L2. IS THERE ANY OUT THERE THAT CAN HELP ME, PLAIN ENGLISH PLEASE.