Open the display cable connector by using a plastic opening tool to flip the latch upwards.

The display is held in place with a mild adhesive. A spudger helps you to get it free.

Now you can unplug the cable and take out the whole display.

After reassembly you want to perform the three function tests (0, 1 and 2) from the OP-1 special start screen. You can enter this menu by holding the COM key when powering up.