Here's one way to do it:
First, rotate the part and place the cursor so it's in front of the face you want to select. Take your hand off the mouse.
Next, press the up (or down) arrow on the keyboard. A circle will appear with a list of all the features that are behind the cursor. Press up arrow several times to scroll through the list of features, notice that each one is shown inside the circle.
Once you've scrolled to the inside face you want, and it's hightlighted, press the Enter button to select it.