DRIVERS SIDE
C501 (Green Plug CJB) PIN 5 take a OG/YE 0.35mm wire to PIN 6 on the seat switch
C501 (Green Plug CJB) PIN 10 take a GN/YE 0.35mm wire to PIN 4 on the seat switch
C31 (Blue Plug CJB) PIN 1 take a GN/BK 1mm wire to PIN 9 on C60 -> C60d PIN 8 on the existing PFL switch - BU/RD - Illumination to PIN 3 on the new switch
PIN 4 on the existing PFL switch - BK - GROUND - to PIN 1 on the new seat switch
PIN 2 on the new switch take a WH/GN 0.35mm wire to Pin 17 on C60 -> Pin 1 C60h on the seat connector. This is the program wire telling the seats to cool or heat.
PIN 2 C60h (seat side) goes to PIN 18 C61h (car side) to GROUND
Pin 2 C60d (seat side) goes to PIN 10 (car side) to GROUND
PASSENGER SIDE
Power, Illumination and Earth wires are the same as the drivers side. As the switch is an integrated unit on the FL no other wires are required.
To power up the passenger side...
Splice a wire into GN/BK 1mm from C31 (Blue Plug CJB) BEFORE it gets to the seat connector (Driver side) Run this wire to PIN 9 C61 -> C61d on the passenger side
Splice a wire into WH/GN 0.35mm BEFORE it gets to the seat connector (Driver Side). Run this wire to PIN 17 C61 -> C61h on the passenger side
PIN 2 C61d (seat side) goes to PIN 10 C61 then to GROUND
PIN 2 C61h (seat side) goes to PIN 18 C61 then to GROUND
Index to symbols / accronyms
PFL - Pre Facelift FL - Facelift CJB - Central Junction Box C61 (etc) refers to plug numbers.

although i'm sure that alex will want the recognition (because i think he's the guy who figured it all out) if you blow your car up no one will accept responsibility if the wires are a different colour on your motor

www.talkford.com is where you need to be to get any further assistance as this is a fairly regular swap