1) Remove the trim from the door. Not documented here, but there are videos online that will help you accomplish that. Separate the insert part from the rest of the door trim by removing the plastic welds. You can hot-glue them back later.

2) Test-fit the insert covers to make sure you know how to align them on the door.

3) Use a spray adhesive or contact cement.
4) Make sure you apply it correctly - read the instructions on the glue container regarding application and cure times.

5) Glue the insert cover on the door trim. Allow the glue to cure, then re-install back in the car.

ENJOY YOUR NEW LEATHER INTERIOR UPGRADE :-)
Useful tip:
You have installed a product made out of genuine leather. As you know, to maintain a leather product in good condition, you should take care of it. We suggest occasionally (every 4-6 week for example) applying some leather conditioner/UV protector to keep your leather from drying up in the sun and cracking.
Redline Automotive Accessories Corp. will not be held liable for any labor, incidental or consequential damages of any kind. Proceed at your own risk.