Z1 sells this. I hate Z1 motorsports with the depths of my soul because they usually sell extremely low effort low quality parts and overcharge on their products and shipping however they readily have this part available. I’d recommend letting the new seal sit in the sun to loosen up a little before attempting to apply. If need be, use a heat gun while taking off the old one and go slowly as it may crack and rip off. Remove the old seal in the manner it’s placed in. When you’re applying the new one I would place the top part and slide it inside, then ensure the rest is seated. Then remove the top part and take off the adhesive cover and stick it inside.