Okay Andrew, well I have a European '92 Escort CL, if you remove the plastic housing from around the steering column you should be able to see a black plasic box with the stalk protruding from it, there will be some wires coming out too.
Its held in place by 2 screws on my car, so I hope its the same on yours. All you have to do is get a new switch unit (any decent auto-parts shop should do one), and then remove the old one, and fit the new one as an exact reversal of the procedure (make a diagram of what goes where, especially wires and their colours) before starting so you have something to refer to if you feel uncertain.
Whack the covers back on, and Bobs your mothers brother

Ozzy

PS. Put the screws somewhere safe!!! I'm a champ at loosing bits......