Before you do anything, ask yourself if the noise you hear seems to be coming from under your feet while you drive. The location of the rear control arm bushing is roughly under your feet at the floor boards and usually you will hear a thunk around your feet if the bushing is shot.

If you suspect that the noise is coming from the area of the wheel, it is likely another issue: perhaps strut mount, strut itself or issue in the wheel assembly. I'd get a second opinion.

As far as replacing the bushing you speak of, yes, you can unbolt the control arm bushing bracket and then remove the bracket from the control arm, leaving the front of the arm on the vehicle.

jason