Display problems- display cable disconnect/ reconnect?

I am looking on advice from owners who have detached and reconnected the display cable on their 6P? Is it easy to do? Aside from getting to it (I have watched some tutorials) does the ribbon cable just snap off then back on?

Here's my problem...

When I go to activate my screen, it sometimes will light up slowly from black to bright green, or it will stay black until I tap it a few times. Usually if I drop it on it's face from a few inches to a hard surface (I have it in a case) that will do the trick. Sometimes it just won't come on even after tapping it very which way...

Thanks for your help,
JC