Matty's first 1st Gen

my left front caliper is seizing slightly, and it pulls a bit, and drags a bit when not braking, thats not the huge problem(i hope) my brakelines to the rear drums are rusted through, and leaking slightly, how difficult is this to fix, I've bought new shoes, pads, caliper rebuilding kits, and i will buy new lines,

Is this a huge job?

any tricks?, or things to look out for?

Matty's first 1st Gen

Anyone ever experience this?