Rusty at this. Can't figure out how to delete part of a group of objects.
I've never been very good at Illustrator, and haven't used it in three years, but now I have a new job and I need to redo the company logo since they don't have a higher resolution copy or one that's a vector file. The part I'm haveing trouble with is a group of boxes that has a swoop cut out of it.

I have tried making a group of square objects, grouping them, then using the pen tool I draw the area I want to cut out and applying a clipping mask, but that takes away everything I want to keep. I've tried other things too, but nothing works. I'm sure I'm just missing some criticle step. I appreciate any help you can pass along.
Frustratedly,
Tony