As Always Make sure you have turned the water off first. Turn the faucet on to be sure there is no water coming out of it.
All images are thumb nails, you can click on them to see a larger image
First get a delta repair kit from any plumbing supply. If you have a vegetable sprayer you should get a new diverter also. Click on Any picture to see a larger image This is all you will need, Plumbers grease (do not use any other type of grease), your repair kit and your diverter.