Use the flat end of a spudger to pry up and disconnect the display and digitizer cables from their logic board sockets.

To re-attach press connectors like this one, carefully align and press down on one side until it clicks into place, then repeat on the other side. Do not press down on the middle. If the connector is misaligned, the pins can bend, causing permanent damage.

These cables are very delicate, and the connectors can damage easily if they're misaligned. When you reattach the cables to the logic board, try to have as much slack on the cables and gently press the connectors onto their sockets.