ok, so it sounds like you just have a small back. Let’s say you also want to take in the waist by 2″. You can do both in 1 step. The center back of the pattern (even if place on fold) should be a straight line. just measure from this line 2″ or whatever you want to take in, and fold on that line and that becomes the new center back line. That will remove the excess in the center of the back bodice.