I am assuming you already have one switch controlling one of the lights.
Route 3 core and earth cable (6243Y) from the existing switch to the new one. Both switches will need to be 2 way, with 3 connections.
Where the existing switch was, connect the brown (or red) wire to L1 together with the brown of the cable you have just routed.
Connect the existing blue (or black) to L2 together with the grey of the cable you have just installed.
Connect the black of the cable you have just installed to the terminal marked "C" or "common".
The blue (or black) from the existing wiring should have a brown (or red) sleeve around it; you should put some brown sleeving around the black and grey conductors that you have just installed to indicate that they will become live.
Wire the new 2 way switch in the same way, apart from the absence of old wiring.
Remember to sleeve the earth wire with green and yellow sleeving and connect it to the backboxes, and then connect it to the switches if you are using metal clad switches.
At the light fitting you should have a brown (or red) wire and a blue (or black) one. Simply connect some twin and earth (6242Y) between these and your new light fitting, being sure to remember the earth wire, again sheathed in green and yellow sleeving.
If you are in any doubt get a competent electrician to have a look.
Adam
September 2008
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