Suspension, Brakes, Tires & Wheels - rotors

i have a set of brembos for my front brakes but i can't swap them because the caliper nut on the top is being a pain in the ass. does anyone have any ideas on how i can loosen it. i dont have access to an impact wrench(which would make my life easier)

PB Blaster or Liquid Wrench . . . lots of it. And a heat gun, or a torch; or if you don't have one, you can use a hair dryer. 18" breaker bar will help too.

used my socket wrench with a length of pipe slipped over the handle for some added leverage. And a couple of quick strikes on the wrench with a big 'ole hammer might coerce the nuts to give up there life or death hold.