Haynes manual probably wont help you lol
Might be a bit much, but if you want to give it a go, have a look at it.
footwell lights -
take out your cig lighter, the cable going to the middle of it is the 12v one, take another one off it using a split connector (see below)
get a length of cable (doesnt have to be big stuff, small stuff will do for footwell lights ) and connect it with the 12v cable from the cig lighter and take it to a switch (can get little rocker switches from halfords for a few quid).
On the other side of the switch, take another big of cable off going to the inverter of the neon light.
Just get a kit that plugs into your cig lighter