Rear Brake cylinders hard to change?

[cjoenny89]

I just had the truck up to the Muffler man and had the exhaust fixed and brakes bleed after sitting for close to 30 years and the brakes worked great but now the right rear is leaking from inside the brake drum I am guessing bad brake cylinder. Muffler man says you have to pull the axle out to get to it and min $40 just to look at it is this correct? I don't have a lot of time right now in my life and that is why I took it there in the first place. I just wanted to run it the last few nice months before we had to put it away! Its been a long time coming.
What are my options here? Brakes worked good when I first picked it up but now pedal is soft and brake fluid at right rear tire on floor. Hard to replace cylinder or someone said it can be rebuilt? swap it out easy and re-bleed it?
This winter I would not mind doing a complete brake system but right now after waiting 30 years to get this completed and dad being 81 I want to put a few miles on it with him. please help!