Rotor basically means the same thing as disk. They are the big steel disks that are located just inside each of the wheels- the brake caliper pushes the brake shoes against them, creating friction, and so on. If they are below acceptable thickness, then they will need to be replaced.

I don't intend to scare you, but older cars can have unanticipated problems, such as seized bolts, nuts, and so on. I have heard mechanics say that these things can increase the labor time beyond the standard factory labor time, which tend to be figured for newer cars, still under warranty.

That being said, I hope things go well for you !

__________________
Marshall Welch
Seattle, WA
1982 300D-T