As far as changing the impeller out i just did mine a few months ago. I used a mechanics mirror with an adjustable head to see what i was doing. Then if you get a couple of paint can opener tools from home depot you can slide them between the fins and hook the bottom of the old impeller and pull it out side by side. To put it in i used the oil that came with my impeller and pushed it on as far as i could, then used a rubber mallet to pound it in the rest of the way. Also a note if you have not seen it yet the cover of the pump only goes back on one way so i marked the top for putting it back and getting the gasket seated right. good luck