how do i replace the rear drum brakes in a 2000 chevrolet cavalier?

Try www.autozone.com for the step-by step guide along with pictures for this procedure.
Once at the site identify you car under the heading "current Vehicle"
Next click "Repair Info" on the tabs below the AutoZone logo.
At the middle of the page go to "Your Ride, Your Guide" and click "Become a member" set you username and password
Log-in and click "Vehicle repair guide"
Select the category for the repair needed.
Select (on the left) type of repair needed.
Page opens to your repair info.

how do i replace the rear drum brakes in a 2000 chevrolet cavalier?

Simple.

You remove the old brake (SHOES) and install the new ones.

If my answer is givin you problems and issues because it's too simple and makes too much sense, then all you have to do is let us know.

At that point we'll post a step by step walk through, that even you can understand.

Do you have disc or drum brakes on the rear?

Good video, just checked it out myself.

http://www.youtube.com/watch?v=aaJ6X-uxMGM