How do I extract a CLEAN version of this image ?

One way to do it is to use the Elliptical Marquee tool, which is found in the tool panel. You may have to click and hold on the Rectangular Marquee tool to get to it.

Using the Elliptical Marquee, click and drag to make an ellipse. Since these CDs are perfect circles, you'll want to hold the Shift key while you drag to constrain your ellipse to a circle.

Another modifier key you can use is the Alt key. It allows you to expand/contract the circle from the center instead of from a "corner." You can combine the Shift and Alt modifier keys by holding them down together.

A third modifier key you will find handy is the Space bar. Holding the Space bar allows you to move your selection around.

Remember, you can use these modifier keys together.

Drag and move your selection until your dashed line ("marching ants") are aligned with the edge of your first disc. Once it's just right, release your mouse button. Then hold Ctrl and hit J to make a new layer with the contents of your circle.

Now open your Layers panel (Window>Layers, or hit f7) and click on the "Background" layer. (This is your original image.) Select your second disc and hit Ctrl J again to turn that disc into its own separate layer.

Now you can turn the eyeball off on your "Background" layer and move your two discs around independently.

Hope this helps!