Just did the outer seal on my 2018 36CK2. Here is the seal:
https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1
AP Products 018-312-EKD Black 1" x 15/16" x 35' D-Seal
There is a single screw on the end of each seal that you need to remove. Cut the sealant holding the seal in place and then slide it right of the track that it is mounted on. Do the reverse to install.