I'm trying to remove the innermost panes of my sliding windows so I can
apply a heat barrier window film to the panes that are most on the outside.
That is the manufacturer recommendations if I read it properly. I can
remove the sliding pane easily--just up and out. The fixed pane is, of
course, fixed. I then discovered how they decided to secure it in place.
There are screws coming in from the top in bottom that anchor the frame.
From what I can tell, they screwed it in long ago when the drywall hadn't
even been installed yet, and just ran it through everything. Most
specifically, I see a screw, tip facing out, on both the bottom and top--
against the fixed pane.

How am I supposed to get that out and replaced when I reinstall the pane?