How do I put a waterpump in my 4cylnder Dodge.

There's three different 4 cylinder engines. That's a real big procedure on all of them and is spelled out in the service manual. You'll be messing with the timing belt and if you get that off by a few teeth you'll cause very expensive valve damage. This is not a good do-it-yourself project, but if you plan on attempting it, get the manual through the dealer, not a Haynes or Chilton manual. The dealer I used to work for would photocopy pages for customers so they didn't have to buy a manual, but it's still a good investment.