how to remove screen protector

what kind of screen protector is it?

I've put screen protectors on pretty much everything, and had to (partially) remove them about 50 times as well to get every spec and bubble out from below.  I would try Scotch tape again.  Get a really good seal on one of the corners with as much tape as you can so the binding between the tape and protector can overcome the binding between the protector and phone, and then tightly and consistently pull up and away from the phone at a very narrow angle.  That should get the seal between the phone and protector to break and the rest should peel up.  If the tape starts to peel from the protector first, rub the corner and then slowly reacquire tension in the tape.

You gotta be persistent.  I know the tape peels off regularly, that's why you gotta keep the tape pressed on the corner while pulling up at a very narrow angle until the seal between the phone and protector finally gives.  Keep resealing the tape to the protector, and go tight and slow.