While the opening tool did the lion's share of the work, the display will still be slightly adhered to the case. A plastic card will be necessary to free up the last of this adhesive.

Set the iMac face-up on a table.

Starting from the top right corner of the iMac, insert a plastic card between the display and frame.

Be careful not to insert it more than 3/8" (9.5 mm), or you may damage internal components.