Carefully lift the antenna cable and de-route it from the edge of the phone. Use the point of a spudger to help lift the cable free it from the retaining clips.

If the cable does not have enough room to lift up, loosen this Phillips screw securing the logic board so that the board can give more wiggle room.

Be sure to re-tighten this screw during re-installation.

If the cable snags near the SIM reader, it's likely caught on the SIM tray ejection mechanism. Use the point of a spudger to slide the plastic rod out of the way.

During re-installation, be sure to route the antenna cable underneath the logic board corner.

During reassembly, you can also re-insert the SIM card tray after re-routing the antenna cable.

If you feel any resistance, stop and make sure that the tray isn't snagging the antenna cable.