This video #2 of 7 shows how to loosen the window trim / pillar trim piece.
This 6 minute total series of 7 short videos shows you how to remove and replace a broken window appliqué / trim for a 2015 or later GM (Yukon, Tahoe). I broke the video into 7 short pieces to focus on the key steps.
Here’s a link where I purchased my parts (refine results to select for your year, make, model): https://www.gmpartsdirect.com/search?search_str=applique
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Where’s the first video
I don't recall the exact website that I purchased from but believe it was either GMpartsstore.com or one of the reputable sites that has "GM" in the name. I searched for the part number that was stamped on the back of the OEM part and tracked down the latest part number from the website. Search for "Applique" on the parts website (e.g., gmpartsstore.com) and confirm your specific vehicle. Hope this helps.