If replacing the rear glass panel with a brand new one, you will need to transfer the fingerprint sensor and camera bracket over to your replacement glass:

Slide the blade of a halberd spudger or other plastic pry tool into the opening on the edge of the rear button bracket.

Careful not to push directly against the rear button ribbon cable, to avoid damaging it.

Do not push the spudger in too far, to avoid damaging the rear button.

Continue sliding your pry tool around the bracket to cut all the adhesive holding the bracket to the rear case.

Remove the bracket.