Lift the 5G mmWave antenna off the earpiece speaker and remove it.

During reassembly:

Use tweezers or a spudger to remove the old adhesive from the top of the earpiece speaker and back of the antenna.

If your replacement part doesn't include new adhesive, use a 4 mm x 16 mm strip and pre-cut square of thin, double-sided tape to secure the antenna to the earpiece speaker.

Press the antenna onto the earpiece speaker to adhere it.