This isn't any big deal to solve and the dealer won't be doing anything different than a regular shop will.

Pull the rotor against the lip and rotate the rotor as you pull. This is usually enough to get things going. It might take a few pull / turn actions to get things going. Sometimes it helps to put a pry bar across the wheel studs to help in rotation.

If this does not work, locate the parking cable adjuster and slacken the cable, ( or even disconnect and feed cable back in ) This might give enough space to get things gong.