how do i remove diesel astra estate brake pads?

having read all possible answers my 1999 diesel astra estate as a bosch rear caliper ' do i after take the star torqe nuts off to remove the whole caliper or is there a easier way as they are ''solid'' so to speak . i hear all this about a 7mm allen key but i dont seem to have one on this only a 13mm nut thats at the bottom of the caliper whats like on a pin 'the top pin you carnt get at as it just looks like another pin ..if i remove the bottom bolt will this allow me to hinge the caliper up or will i afto try to remove the 2 star torqe nuts (hope not lol) thanx