How do I replace the waterpump on my Kangoo Trekka?

It looks like my waterpump needs replacing as there was a severe loss of coolant. Is it complicated?(I can see that access may be tricky...(It's converted to run LPG also) and is it a geardriven cambelt and will I have to note the position for the timing? As you probably know there is no Haynes manual available yet. Thanks for your advice. Ollie