iFixit

Stick a suction cup near each of the two top corners of the glass panel.

To attach the suction cups we sell, first position the suction cup with the movable handle parallel to the face of the glass panel (as highlighted in the first and second pictures).

While lightly holding the suction cup against the glass, raise the movable handle until it is parallel with the other handle (as highlighted by the third picture).

If your suction cups refuse to stick, try cleaning both the glass panel and the suction cup with a mild solvent.