The black foil which covers the display connectors is very fragile and likely to rip. To keep the tape intact while peeling it off, it's necessary to use high isopropyl alcohol or an iOpener.

Apply a little bit of high isopropyl alcohol (>99%) to a Q-tip and apply it to the black adhesive foil. Let it penetrate the adhesive for about two minutes.

Alternatively you can place an a heated iOpener on top of the screen to loosen the adhesive. Apply the iOpener at least for two minutes.