As above on the drivers side its alot easier as for the passenger side its alot harder as there is a re enforced metal plate blocking it which takes a little longer.
Ford KA's a well known for the top plastic part to snap off over time there is a design fault in them.
Ford fiesta and puma ones are known to fit if your going to the breakers but I got one from ford for £38
Its about 1-2 hours work with a little know how and a easy job for a diy FORD willl charge you £110 Labour if you dont know how so a indy would be my bet if your thinking about doing it yourself.
There are 4 screws to remove the door card. the handle "if they are manual windows" has a C clip on the inside to remove and DONT LOOSE IT!!
The handle once through only has 2 screws and jobs done..
Jay
December 2009