The glass panel is fixed onto the front bezel with fourteen magnets around its perimeter.
Stick two suction cups to opposing 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. While lightly holding the suction cup against the glass, raise the movable handle until it is parallel with the other handle.
If your suction cups refuse to stick, try cleaning both the glass panel and the suction cup with a mild solvent.
Gently pull the glass panel straight up off the iMac.
The glass panel has several positioning pins around its perimeter. To avoid shearing these pins off the glass panel, be sure to only pull straight up during removal.
Be meticulous about cleaning the LCD and the inside face of the glass panel before reinstallation, as any fingerprints or dust trapped inside will be annoyingly visible when the display is on.
When replacing the glass, be sure there's nothing between the glass and the frame. Stray cables could be damaged or crack the glass.
Remove the following 12 screws securing the front bezel to the rear case:
Eight 13 mm T8 Torx.
Four 25 mm T8 Torx.
On the 24" iMac Intel Model A1225, the bottom center two screws are long (26mm), four on sides (two left, two right) are medium (18mm), and the remaining 6 (four top, two bottom corners) are short (14mm).
With the display panel still lifted, disconnect the four inverter cables.
During reinstallation, place the four inverter cable connectors in voids between components attached to the rear panel so the display panel will sit flush on the edges of the rear case.
(combined into one plug in on the 24")
Be sure to keep track of the cables, as they do not have proprietary sockets. Mismatched cables can cause screen issues.
Disconnect the DC-in cable by simultaneously depressing both locking arms and pulling its connector away from the socket on the logic board.
After both locking arms pass their retaining tabs, it is helpful to push them toward the left edge of your iMac with one hand while pulling on the body of the connector with your other hand.
Pull the SATA data cable straight up off the logic board.
The SATA connector on most iMacs tends to stick in its socket on the logic board. If you are having trouble disconnecting the SATA cable, insert a metal spudger or any other thin tool into the gap between the SATA connector and its socket and twist the spudger's shaft to safely separate the two pieces.
Pull the power button and CPU fan connectors straight up off the logic board, and pull the ambient temperature sensor cable toward the lower edge of the iMac.