rotarenvy

I tried to undo the bolt on the lower guidepin on the front caliper to swing the centre section up (like when you change brake pads). I noticed that the pin had a nut on the inside but the brake tech manual that was on the net dosn't mention if you have to loosen the nut or just hold it still? before I force something and damage the caliper I thought I should ask if I just need to unscrew the bolt at the rear or do I need to do somthing with the nut on the other side like loosen it off or hold it still?