This operation is quite straightforward. After putting the machine on a stand the cooling fluid has to be drained. I always use regular car-type cooling fluid as this gives a totally clean engine all the time. With water you only get heavy calcium deposits. Start by removing the r.h. hose to the waterpump and the fluid can be caught in a clean tray. I filter it and re-use it! Next loosen the ventplug on the cylinderhead and the brass drainplug on the cylinder in order to drain the last fluid. Loosen the clamps on the hose from the cylinderhead to the radiator.

Yamaha TZ350G, waterpump