Is replacing a whole toilet system something a clever novice could do?
Whether you are talking about replacing the entire toilet (porcelain and all) or just the inner workings of the tank, it is easy. Read the directions. Use teflon tape at applicable locations and wrap it the correct direction ( so that when you twist the pieces together, the motion doesn’t want to un-ravel the tape).When you disconnect the supply line, take it off at the tank instead of at the valve and you will have one less connection to make. It is easy-peasy, and the replacement parts are inexpensive. If you can’t do it (which I doubt) you haven’t lost much. Go for it. You will make yourself proud!