OK! this is a very easy interior mod in my opinion. Theres a certain performance website out there asking for £160 for this kit I did it for around £35 and 30mins of my time

So here's how I did it

1) You will need

A light unit from a focus (black or beige)
16 gauge wire Red (from maplin), there's 10mtrs here but you'll only need approx 2mtrs
A small female spade connector (like you would use for audio speakers)
A small Blue scotchlock
Crimpers



This is the submarine lighting connection your looking for(circled):



2) Crimp you spade connector onto your red wire (excuse the rubbish crimping lol):



3) Check for a snug fit:



4) Go out to the car and carefully remove your old interior light using a large flathead screwdriver or (like me) a butter knife wrapped in kitchen towel :



5) Disconnect the 3 plugs, then feed the ambient lighting feed through the gap between the roof lining and windscreen:



6) Feed the wire behind the roof lining across to the 'A' pillar and then down to the dashboard:



7) Now carefully remove your light switch unit from the dash (again using a screwdriver or knife):



8) Then disconnect it from the plug.

9) Slowly pass the wire through the gap bewteen the A pillar and the dash, I had to reach into the hole until I could feel the wire and pulled it through.

10) Next you need to look for the Orange/Blue wire (this means mainly Orange with Blue line) on the loom.

11) Use the scotchlock to connect the red wire into this:



12) Now connect the red wire onto the replacement (Focus) unit, re-connect the 3 standard connections and clip it back into the roof lining.
13) Re-connect the lighting unit to the plug and test it by clicking the sidelights on....






14) Finally, tidy up the wiring along the A pillar, re-fit the A pillar plastic and weather strip, re-fit the unit into the dash.

Just to prove it all works for any doubters out there



Hopefully this will help someone wanting to do this