iPhone 6 frame screw removal

Good afternoon....

Replacing the cracked screen on my iPhone 6 (not S or +.)

I'm at the step where I remove the 6 Phillips screws from the digitizer back-plate so that the plate can be removed.

Tw of those screws simply spin in place, and will not come out. They are not stripped. Specifically, looking at the face of the phone, it's the bottom left and top right screws.

Watched a ton of videos... one mentions that these screws are tough: https://www.youtube.com/watch?v=CXlTVa5t...

The catch is, due to an accident, I only have one arm! So, holding pliers up against the frame as shown in that video is not happening. Also, no other video mentions this trouble.

Am I just a numpty? What am i missing to get these screws out?