Thats one of the bolts fella, no pins or l/h thread, mine were just super tight, and when initially turning dont seem to look like they are moving. I had to jack the car right up to get a breakers bar on them. WD-40 it, or get some penetrating oil overnight should work.
The other bolt is the other end of the caliper, identical to the one in the pic. You need to undo both to get a new disc on. And remember to support the caliper so you dont strain the brake hose! (bungee cords are good)