I would start with resetting the connectors on motherboard side and then on the screen side. Then I would try replacing cables. Anything above that would require multimeter knowledge. Always start from cheapest to more expensive.

Worked for me with 2012 13” perfectly fine.

Don’t remove glue. Just reuse it by heating and sticking it again.

I’ve managed to do it using hair dryer on max. First corner was though and took a lot of time to lift it. I decided to heat not only a corner but whole length and then it came off. I’ve put so much heat that was afraid I’ve damaged LCD, but it works fine. As BillyRachel1 said: patience is the way. In order to assemble it back I used old glue heated again. It’s easy but takes time.

Note: Don’t do this at home if you have cats otherwise you going to spend next hour or so trying to remove their fur from between glass and LCD. It’s because they all levitate after using hot air and just wait to stick to the screen again.

To be honest hardest thing was replacing clutch cover, took me so much time and I eventually cracked it.