First off you will need to remove the screws that hold the handle, door pockets and also the surround to the door handle.
Next you will have to remove the retaining clip on the window winder, to do this you will have to gently pull the winder away from the door while trying to remove the clip with the aid of the small thin screwdriver.
To remove the door latches you need to carefully peel back the polythene membrane on the door - DO NOT rip this as it keeps moisture form the door panel. Then you need to unscrew the three retaining screws that are located on the side of the doors using the large pozidrive screwdriver.
Fitting the central locking latches is simply the reverse of removal, when screwing the latches in it helps to have another person hold the latch in place while you start to thread the screws. However do not replace the polythene membrane yet.
Once the two motors are in the doors it is just a case of linking all of the wires together and running the red and yellow wire to a red wire in the fuse box and the brown wire anywhere in the car. For the red and yellow wire and also the brown wire make sure that they are joined so that the wire still has a "loose end" and has not formed a "loop".
To join the wires together you first need to pass the wires through the rubber grommet between the door and the shell, at the shell side of the grommet is a plastic multiplug, Here you have two options, remove the multiplug and have the wires running straight into the car or you can get both ends of the multiplug, with a short length of wire on each half of the multiplug, off of a high spec fiesta that has had an untimely end ( ie local Scrap yard) and attach the wires to the relevant wires on the multiplug.
Once all of the wires from the drivers door have been joined to the passenger door you need to connect the joined brown (earth) to a suitable earth, any brown wire in the car would be suitable but I chose one in the fuse box as I was running the power into there as well to make life easy. Simply connect the
already joined red and yellow wires to a main red power feed in the fuse box that does not need the ignition to be switched on to operate, I chose the power feed for the horn as the power feed for the central locking. First run the red and yellow lead to which ever fuse holder you are using, then simply Connect a wire from the other end of the fuse holder to the chosen red wire using a scotchloc connector.
Now all that is left to do is reconnect the battery test the central locking and put the door trims back on.
Red/yellow wires = live feed - needs a fuse in before the motors.
Brown wires = Earth
Yellow wires and white wires = locking wires