when my pump went bad. the only thing we really had an issue with was putting the tank back on. the straps faught us hard. but once we got them lined up, done deal. rather easy. you will need help for sure, need someone to hold the tank up while you try to get the straps started on the bolts. we ended up using a jack to help hold it up. it took a while.
as for the amperage, thats beyond my knowledge. one of the mods here can answer that for ya...