I wonder if there is an issue with the individual file of mine, since you were able to achieve the desired result. I am following a step-by-step exercize from the book “Woodworkers Guide SketchUp”, by Bob Lang(I am an aspiring novice at SU). Based on your input I got an idea for a work around that did not involve exploding the component in question(just editing, as you suggested), and it seems just as easy and efficient as the original technique.
Thanks for you help.