Hi,
You may be out of luck in just trying to replace the webcam module.
According to the [https://topics-cdn.dell.com/pdf/xps-15-9570-laptop_service-manual_en-us.pdf|service manual] (taken from [https://www.dell.com/support/home/us/en/04/product-support/product/xps-15-9570-laptop/docs|this] webpage), in the display assembly removal procedure section, once the display assembly has been removed from the palmrest assembly, it states on p.62:
“ ''The display assembly cannot be further disassembled. If the display bezel, display panel, '''camera module''', display cable and touch-screen cable (optional) are defective and need to be replaced, replace the entire display assembly.'' “
I have found a [https://www.parts-people.com/index.php?action=category&id=143&subid=1201&refine=web+camera|web cam module] replacement part (supplier example only to give idea of what it looks like and the cost) but cannot find out how to safely dis-assemble the display so that the webcam can be replaced. You may have better luck.