Hello Tanner,
Welcome to Communities,
You can de-register the In-Active\Stopped Collector and the options to remove retired collectors from Cloud Services Platform’s Skyline Collector Service.
Log in to CSP Advisor Portal ( https://skyline.vmware.com/collector/manage-collectors ) > Click on the 3 vertical dots on the actions column and you will see options to Deregister.
& another option would be to navigate it to Skyline - Getting Started at Step 5 (Manage existing Collectors) from the listed Collector Id under Actions Select Deregister.
Regards
Vishwajit Shah
Skyline Support Moderator
VCA-DCV | VCP5-DCV | VCP6.0; 6.5-DCV & CMA | VCA-DBT | VCAP60-DCV