Unless you are getting scraping noises out of the rear brakes or fluid is dripping out then you might just need to adjust them instead of replace them. Try pulling the parking brake 1/2 way on and see if that helps the pedal travel. Depending on the year it could have several types of adjusters - my 544 has a little slot through which you can turn a toothed wheel with a screwdriver (invariably the wrong direction on the first try). Yours might have this or a little square head at the bottom of the back plate.

If you do need to pull the drum you'll need a really heavy duty stud puller. Some auto parts stores have these available for rent, or they are for sale new for around $120. I got lucky and got one on eBay (ex-military) for about $60.

http://www.mytoolstore.com/otc/7394.html