It's doable but I wouldn't recommend doing this job on something you want to drive if you've never done a drum brake job before. Knowing what kind of vehicle you are working on might help this decision easier, as the job is easier on some vehicles than on others.
That said, if you're fairly good with automotive stuff you should be able to follow the instructions in a Haynes or Chilton manual and get the job done yourself. You'll be much happier if you purchase (borrow?) a drum brake spring tool with a hold-town tool on one of the legs
to make removing/installing the return springs and hold-downs easier - the job is a nightmare (and a potential "knuckle-buster") without it. An adjusting tool for the "star-wheel"
is also nice to have, but not as important as the pliers.
One very important point if you do decide to tackle this repair...take both drums off and leave the shoes/springs intact on the backing plate on one side while you do the other. You'll have a reference to how the springs and shoes go on that way...it's very easy to forget which hole a spring goes into, how the star-wheel goes together, and which shoe is the leading or trailing one (the linings are usually different lengths).
You can do this job on some vehicles without bleeding the brakes, but only if you leave the wheel cylinders in place and don't remove the metal brake lines attached to them. However, it's always a good idea to replace the cylinders, anyway...they're not usually very expensive and prone to leakage if you continue to use an older one. If you do decide to replace the cylinders, you might consider buying/borrowing a hand-held brake bleeding tool
like this one. It makes bleeding easy and thorough, and keeps you from having to retain the services (and train) an "assistant."
Only you can decide if you have the ability to do this job. If you do, I and many others here can assist you with "on-the-fly" instructions if you run into trouble. Go to your library and see if there's a free repair manual for your vehicle that you could copy the pertinent instructions from. Best of luck!