Try going to You Tube and type in "How to change fuel pump on a 2003 Pontiac Grand Prix" There are some excellent videos there. Also, most mechanics have a book that tells them how long it should take to do a job. When they give you a price it is based on the book. So if the book says a job should take 2 hours, that is what they charge you. If it takes only 1 hour to do the work, they make more money. If it takes 3 hours, it may cost them as they are supposed to stay with their estimate. You can bet they usually don't lose money, because they generally know how to do that work. Occasionally, a job runs into unexpected snags that take them longer to do than the estimate.