They have been squeeling pretty bad. I have 19,000 miles on them. My boyfriend and I took the tires off and blew out bunchs of brake dust and they aren't nearly as bad. But we couldnt figure out how to get to them. There is a round silver cap in the middle but we didn't know if it comes off first or what. He knows how to work on his ranger. We have fixed all kinds of things just by getting the great info off of the ranger site.
It's been a while since I have pulled drum brakes and on much older cars but if things haven't changed too much............Of course take off the wheel, the round silver cap you mentioned, remove that and there should be a nut behind that with a cotter pin through the shaft to keep it in place. Remove the cotter pin and screw the nut off. You should then be able to remove the drum and expose the brake assembly and pads. Do the reverse to reassemble.
Unless the focus drums are of an unusual design the drums should just pop off. There should be couple of holes drilled in the drum which are located located between several of the wheel studs. Get two bolts of the correct size and screw them into the holes (usually the holes are the same diameter and tread pattern as the wheel stud), as you screw the stud in it will pop the drum free.