Please provide me with instructions on how to replace a pull string switch on a ceiling fan
Light.

Brand and model would help us greatly. Basically open the canopy and look inside. The switch is usuaully on the outside ring of the housing held in place with a round thumb nut inside. The wires , 3, are connected with wire nuts. Can't give you wire colors unless I know more about the fan and if this is a light switch or fan motor.