I need white frame around the screen instead of black

The black coating is directly on the glass and between glass and the digitiser. Those are glued together by optically clear resin, probably UV cured. It is possible to separate them with a nylon string used as a kind of string saw. The digitiser however is extremely sensitive to any damage. You would need to get some of that resin to get it back together.
It is probably easier and a lot less risky if you get someone to cut you a white vinyl sticker to put on the glass with a vinyl plotter and maybe try to paint the case white. Take caution to not get the button stuck with paint.