Rear brake caliper

What is the bracket assembly with a small spring bolted to my rear caliper on a 2014 corolla S. How do I remove it from the caliper in order to get the caliper off? Do I need to remove that spring in the process?
isnt the S model with disc all the way around, or is this the example of S and S premium like in other threads... my 14 S had disc brakes all the way around and the spring part was part of the ebrake system.... heavy on the brakes or something or just considering a swap over for performance ? seems like the brakes are getting longer life lately... i did a brake job on my 2012 gmc terrain at like 125k... used drilled and slotted rotors... boy they looked sharp... look to see if they have some rotors like that... that like nice on a 14 S