Melt chocolate in a bain marie (bowl over simmering water). Make sure the bottom of the bowl does not touch the water, as this would spoil the chocolate. You could also melt the chocolate at a low setting in a microwave.
Stir in the margarine until melted, then add the milk, coconut and icing sugar.
Mix until well combined and smooth.
Once cool, roll into balls and roll each ball in coconut and sprinkles.
Store the truffles in a container between layers of greaseproof paper. These will keep in a cool, dark place for up to a month.Notes: I made 14 truffles, but how many you make will depend on the size.