Just done that couple of weeks ago! On the left of the steering wheel, four buttons for light switch, all original. The fuel switch is now on the above the coin tray.
Like I did:
(0) Disconnect the battery. I didn't and the fuse burnt
(1) Pull out all the switches on both sides of the steering wheel and deconnect them. Mark the fuelflap connection and then press all the connections inside.
(2) Remove the sun cover of the speedometer, that's two screws shown on the picture as "2". Behind the sun cover, there are two clips. Just pull easy on the cover and they will pop loose. Put it away
(3) On both sides of the speedometer, there are two screws. (nr "5" on picture) Take them away and the whole unit will come loose (no worries) There is enough cable to put it in the middle of the dashboard so it is not in the way and so you don't have to disconnect it.
You can now see where all the cables are going too. First i wanted to relocate the connection without cutting it. This was not an option for me. The wires go behind the dashboard and you can't get to them because of all the aluminium tubing etc. So what I did:
(4) Follow the wires to the hole behind the wheel, where you can't see them anymore. There is a tyrip. Cut it, so you have more cable. Cut the wires, 4 of them, about 8 cm from the connection. Take some 0,75mm^2 wire and cut 4x 50cm of it. Connect these four with the original wire by soldering etc.
(5) Now take off the switches above the coin tray by just pulling them too you. Usually the whole plastic harnas comes with it. Disconnect all the connections. Now the new wires have to go from the hole behind the wheel to that place. Try with something stiff (metal thread) to get from that place to the steering wheel. It's quite easy
When your there, pull it back with the wires.
(6) Now connect the wires with the original connection and check if you do the right color to the right color. Connect them with soldering etc. Connect the switch and it would work
(7) make sure you do a new tyrip behind the wheel so all the wires will stay in the right place. Now reinstall everything anti clockwise
Before you start with this, make sure you have the right fuelswitch, wich can be bought from ebay for a couple of bucks. Also buy a new switch for the open spot you've created, this can be a blank one or something new!
I will post some pics tomorrow or something. It looks very neat and the car will stay original if you need two more light switches on your dash!