Sorry, my original reply was a bit rushed. Not changed one before but it strikes me as an easy job (or should be). If the fixings are the type that you screw on you should be ok to reuse. If you have any kind of plastic clips or spring loaded ones then replace them. The reservoir itself just lifts out of its mount, tough i have not followed the pipes through to their other end to see how easy access is.

Dont forget your antifreeze and if you are feeling brave now may be the time to renew the coolant. Haynes manual says it all on that one, i followed it the weekend when i replaced the Timing belt, water pump etc

Good luck