My bathtub faucet is leaking, but I don't know how to remove it. Can you give me some pointers?

Remove what? The cartridge/stem? The entire valve?
Where's it leaking from? One handle or two knobs?
Back to you, Tom

I'm not all that familiar with what type of faucet I have or the terms used to describe them, but, it is a bathtub/shower faucet which has 1 faucet and 2 knobs above it , 1 for hot water and one for cold water. On top of the faucet is a stem that you pull up in order to use the shower. The leak is coming from both sides of the bottom of the faucet. I was assuming that I needed to remove the entire faucet in order to see where the leak is, but maybe I don't need to. The plumbing is approx 40 years old.

Is the water leaking from around the hot and cold sides when you turn them on? Or someplace else?
Let me know, Tom

No, the water leaks directly from the faucet, not the hot and cold water handles

the water leaks directly from the faucet,
By "faucet" do you mean the valve or the spout? Regards, Tom

The leak is coming from the spout

Either you have some washers that no longer seal por you have a cartridge or ball valve that has bad seals too. All can be repaired if we can narrow the brand dowm. Any chance you can post a picture?

OK! Gotcha!
Sounds like your washers need replacing. Here's some help; Bath Tub Faucet Drips - Replace A Faucet Washer To Stop Leak At Spout (http://www.hammerzone.com/archives/plumbing/faucet/washer/replace.htm)
Here's a cutaway of your type of valve, (see image) After you remove the stem assembly check the seats fro rough spots or nicks. If you find any they must be replaced otherwise they will just tear up the washers. N Good luck, Tom