It depends. High quality brakes can last a very long time if you drive your car properly and do not rabbit drive. If they are squeaking, you should have them checked out.
Most places charge by the hour, but the having your drum brakes replaced could cost anywhere from $200 to $600 depending on how bad the drum brakes are.
You will be pleasantly surprised to find that you can change your car's disc ... could either be disc or drum brakes), so they need to be changed more often.
Once you get your brakes off, I would use a screwdriver to loosen the brake drum. It should come off easily after that.
replaced
Disk brakes should appear as shiny plates with the calipers on top and in full view. Drum brakes will appear as a 'bowl' which make telling them apart instant.
Car brakes have become easier to replace since the disc brakes replaced the drum version. If you have mechanical abilities, the correct tools and a day to devote to the task you should be fine. The auto supply store that sells the brake pads to you should recommend a manual for you to follow.
Disc brakes are not subject to "fade" which occurs when drum brakes overheat and lose the ability to stop, another advantage of disc brakes is that they tend to stop in a straight line unlike drum brakes which often "pull" to one side. Yet another advantage of disc brakes is that they self adjust by drawing brake fluid in behind the piston while it is common for the self adjusters in drum brakes to seize due to corrosion then the drum brakes quit adjusting then the brake pedal goes lower and lower.
If the rear brakes are drum brakes remove the wheel slide the drum off and check brake lining if brake lining is good then at the bottom of the brake assembly turn the adjuster wheel out. Check by putting drum on and spinning the drum until it spin 1 to 1 1/2 times around. If the car has rear disc brakes check brake pads probably needs to be replaced
Disc brakes are more powerful, but it's easier to add a parking brake to a drum brake. So the front wheels often gets disc brakes, as they do most of the braking anyway, and the rears get drum brakes.
( 1 ) on each of the rear drum brakes
Yes, of course you can adjust the rear drum brakes. They should be self adjusting. Every time you back up and apply the brakes they should adjust themselves. If that is not working, look for a small rubber plug on the back of the backing plate. Remove that plug and with a brake adjustment tool, you can adjust the brakes. Search Google for the proper procedure to adjust drum brakes.
What about 1993 Pontiac drum brakes, please be specific.