Well, it's a sort of big topic, and I wouldn't feel good writing out a bunch of directions on how to rebuilt a drum brake. A repair manual would be a good thing if you haven't done it before.

But for a basic start - take a hammer and gently tap off the grease cap at the center of the hub (the sheet metal cap that pokes out from the center of the drum). Underneath is a nut with a pin. Remove the pin, remove the nut. Wiggle the drum around and the keyed washer and outer bearung under the nut will come out, remove and place out of dirt's way. Then the drum *should* slide off, although if the shoes are nice and snug you might have to back off the adjustment.

To adjust the brakes, there is a little hole at the bottom of the back plate. You work completely blind, but you have to reach into that hole with a screw driver and turn a toothed wheel - that screws an expanding link in or out. Quite often on cars that have been sitting around for a while they are rusted and sticky. If they will budge, keep going one way until either the drum comes off or it freezes in place. If it freezes into place you were going the wrong way, go back the other way until the drum will slide off.

Once the drum is off, the way everything fits together inside should be fairly self explanatory. Some vice grips helps to grab the springs and lift them off the shoes, possibly pried with a lever for a more controlled lift. The fronts are fairly straightforward, the backs are a little more complex with the parking brake levers integrated into the mix. While apart, take the opportunity to disassemble and thoroughly clean the adjuster - put it back together well coated with brake grease (that stuff they sell for caliper slides).

Once working, you will need to adjust the brakes through that hole with a screwedriver every 5 - 10K miles, more or less. The 'slack' travel of the brake pedal will let you know when you need to do it again.
--
I'm JohnMc, and I approved this message.