Need to fix water supply to rear windscreen washer - 06 Mondeo?

My rear windscreen washer on my 06 Ford Mondeo has stopped working - it could simply be that the tubes which carry the water have come apart with the freezing weather? Where do I access the tubes to see if it is a matter of just re-connecting any joints that have 'popped' apart? Many thanks to anyone who can describe how - much appreciated