Turn the screen assembly over.

Insert an opening pick in between the LCD panel and the digitizer at the top-left corner.

It doesn't matter how deep you insert the opening pick, but about 5 mm is enough to slice through all the adhesive.

You can slightly bend the digitizer to create a wider gap, but take care not to bend it too far to cause damage to the digitizer if you're reusing it.

Slide the opening pick along the top edge of the screen assembly to slice the adhesive.