The graphite sheet is very fragile. Be gentle peeling the graphite sheet in this step, especially if you're reusing it.

The graphite sheet is lightly adhered to the logic board.

Peel the bottom of the graphite sheet toward the top of the phone until you can access the bottom bracket.

Use your hands, or tape with light adhesive, to keep the graphite sheet out of the way.

During reassembly:

If you completely removed your graphite sheet, follow this guide to replace it.

If you don't have custom cut adhesive strips for the antenna, use double-sided tape, like Tesa Tape, to secure the graphite sheet to the logic board.