However, before you pull the thing apart have you checked to see if the tell tail is blocked rather than the water pump being stuffed. The tell tail will be supplied by a thin hose from the block. Pull it off from the block and run the engine
, if water comes out, try a thin piece of wire up the tube.
If you have to replace the water pump it will at the gearbox
join in the lower leg. Normally sits on the ling vertical drive leg and covered with a stainless steel
cover which bolts down on to the gearbox
Grease the drive shaft top splines before you bolt it together again or risk a drama in years to come.