Cheaper and easier to just replace the wheel cylinder. If the brake line is rusted any, you might as well figure getting a new brake line as well. I've replaced tons of wheel cylinders without disturbing the brake lines though. You basically crack it loose, and unscrew the cylinder.
If the bolts holding the cylinder are rusted any, or the car has a fair amout of age and miles on her, you can either give some heat to the cylinder, or cut the heads of the bolts off, and put new bolts in with the wheel cylinder.
I find if the bleeder screw won't come loose when you're doing brake work, to give it some heat with a torch, and it comes out easy. You gotta be careful you don't break it off, you will feel it. If you're doing front calipers its especially critical you don't break that bleeder screw as the parts stores won't give you your core credit back. My dad broke the screw off his sunfire, had to weld 2 nuts on the screw, and heat it nice and cherry red before it would budge.
If you have those drum brakes with that single return spring, they can be a pain doing them for the first time. I remember my dad telling me years ago i'll figure it out too, lol.
When all is done, make sure you adjust your brakes to the point where they are dragging slightly on the drum. The tire should not spin more than one full revolution on its own, but it should not be so tight to the point where you can't turn the wheel. This might require removing the drum several times, and it helps to grind down that ridge of rust on the drum, makes it easier to remove and replace.
When all is done, you'll have a beautiful firm brake pedal.
2009 Pontiac Vibe AWD 2.4
1993 Buick Park Avenue 3800
1984 Chevrolet Citation 2.5 liter four.