Adhesive pad on the back??? you mean the anti-rattle pad that is a part of the pad assembly. That is completely irrelevant to removing the pads. Also, you don't need to remove the pads and rotors to simply check them. Just pull the rims and look at them.
The calipers come off pretty much just like any other. You remove the (2) caliper bolts holding it to the caliper mounting bracket and you pry the caliper back away from the bracket. One of the very first things I do to a new vehicles is pull the rims, calipers, caliper brackets and the rotors off and apply anti-seize to all bolts and mating surfaces (obviously not to the outside rotor & brake surface). This exercise of mine was no different on my 22' ST or my 25' ST.
**I can't completely remember now but I think the caliper had to be removed by prying back the top and then lifting (or prying) it upward and out on an upward angle. I keep thinking it somewhat locks in-place with the caliper bracket at the bottom. Anyway, its not rocket science and you sure as hell don't need Forscan for it.