If you work the parking brake handle several times, it should take up the slack; the calipers are self-adjusting to bring the pads in contact with the disc after replacement.
I don't know why people are saying NOT to adjust the parking brake cables. I would say adjust to take up most of the slack in the cable without actuating the rear caliper lever. I had to replace both my cables due to sticking in cold weather (ended up with glowing brake rotors) and I adjusted them to be just this side of snug, so there's no free play in the handle. My rear brakes start to engage at the 2nd click or so, but they don't drag at all.
A word of caution, however: ONLY adjust your cables after your rear brakes are already self adjusted. If you perform any brake work, make sure the calipers have taken up all the slack before you adjust the cables.