I just purchased a 2016 RR Sport Supercharged (5.0 motor) with 38k miles on it. Car is clean in and out. The brakes and rotors are done so I got the brakes and rotors from a dealership. I managed to the rear, however, the problem is when I took the front driver side brembo caliper off and tried to press the pistons back, one of them is "stuck/frozen". Would loosening the brake bleeder help push it back? The car is still under warranty for another month, would this be covered under the warranty? Would they charge to look at it? If it is under warranty, will they charge me labor to change it out? Thanks for any info.