To take water pump off you need to take alternator out - it sits on top of the pump. To do that take both aux belts off then just work your way down the alternator, then take top cam belt cover off, that just unclips.
The go on taking off bottom one, for that you'll need to take the pulley off etc. Personally would just go and get a haynes (I did), cambelt renewal is on page 2a-5 to 2a-9 and very well described for the 1.8 and 2.0 8v engines. Sure worth the 15£...