Drain out the antifreeze, Follow the hoses to the water pump and remove them. Remove the belt that is driving the pump and remove it. Remove the bolts holding on the pump and remove it. If is stuck then gently tap it with a hammer to free it. Scrape off the gasket off the block and replace it. If you are using RTV sealant clean the mating surfaces with acetone or lacquer thinner. Using a new gasket , torque the bolts to the proper value. Refill the cooling system. Test for leaks