There are two pieces to the rub rails. If you are talking about only the center piece it is quite simple. No need for any rubber mallets. The rubber just needs to be a little warm. So either on a hot day, or with a heat gun(you do not need to get it very hot) warm up the rubber and I found it easier to press into the center of the rail to install rather than trying to squeeze the edges. once you find the technique you can move around the boat pretty quick. If i did it again i would wait until the rubber cools down before cutting to fit. It will shrink again over the next day or so after installing.
I have never replaced the part of the rail that is riveted to the boat. That looks a little more challenging. I am guessing you will need stainless steel rivets and some sort of silicone or gasket in order to replace that.