Danny,
Drum brakes work by spreading brake shoes outward and causing friction on the inside diameter of the brake drum. As the drum wears, the shoes are designed to keep a small amount of pressure on the drum so as to scrape up against it during normal driving.
This slight pressure is maintained by an adjuster screw assembly, which spreads out when you back up and use the brakes. In order to remove the brake drum, the pressure on the shoes needs to be released by turning the adjuster screw assembly in reverse. This is done by inserting a tool such as a flat screwdriver in a slot behind the drum support plate and turning a toothy wheel to loosen the adjuster. Once it is loose, the drums will slide right off.
Check out these great exploded view of brake drums and be confident, they all work mostly the same.
[http://www.bc4x4.com/tech/2009/drumbrakes/|Here.]
[http://www.liwebmasters.com/el%20camino/schematics%20and%20diagrams/images/Brake%20Drum%20Exploded%20View_gif.jpg|Here.]
[http://www.westerntowing.co.uk/acatalog/Brake_Spares_Diagram.html|Here]
A tip, take both drums off but change only one wheel at a time, use the other side for reference upon reassembly
Have fun.
Frank