Remove the NFC antenna.

When placing the old NFC antenna into a new back cover, apply a heated iOpener for about a minute to it. This helps the old adhesive to adhere to the new back cover.

Compare your new replacement part to the original part—you may need to transfer other components from your old back cover to your new one.

Apply new adhesive where it's necessary after cleaning the relevant areas with isopropyl alcohol (>90%).

Secure the new back cover with pre-cut adhesive or double-sided adhesive tape. Apply the new adhesive into the back cover and not onto the frame of the phone assembly. After installing the back cover, apply strong, steady pressure to your phone for several minutes to help the adhesive form a good bond—a stack of heavy books works well.