Rear calliper dragging, rebuild kit?

Its dragging a lot when i go slow you can hear it rubbing a lot. I was thinking about buying new callipers but should i just find a rebuild kit for it? Somebody please give me some options.

http://shop.advanceautoparts.com/webapp/wcs/stores/servlet/product_Brake-Caliper-Kit-Tru-Torque_18360724-P_223_R|GRPBRHYAMS_611593094___

try taking the calapir off and cleaning the pins that connects it to the calapir bracket they need to move freely so that calipir will pull pads off the rotor

Is the pad just dragging or is it rubbing on the rotor?

I'd just pull them and rebuild them anyway only takes like 5 mins to do, but make sure you check the sliders like stated above if they stick they can cause rubbing.