Use a heat gun to soften the adhesive under the black strip near the upper left corner of the glass display panel.

Attach a suction cup near the upper left corner of the glass display panel.

Pull up on the suction cup and use the flat end of a spudger to carefully pry the glass display panel out of the display assembly.

Once the upper left corner has been separated from the display, it may be helpful to use a guitar pick or another thin plastic object to keep the glass from sticking back down to the display assembly.