Significant amount of force indeed!
I yoyo’d the phone off of one of the battery adhesive strips. The incredibly slippery aluminum case slipped out of my right hand as I was pulling one of the battery strips out with my left hand. It shot across the table and I was sure it was going to rip the adhesive strip. But it held!
Keep a grip on the phone when pulling the battery strips out.
Are the "hex nuts" under the processor board? Could you provide a close up picture of the "nuts?"