On the Team page, find the member in the list and use the remove option. The system asks you to confirm before it finishes. Once removed, the person immediately loses access to Ads Editor and no longer appears in your members list. Use this when someone leaves your operation or should no longer have access to the accounts. Because members never had their own Meta or Google credentials (they used your connection), removing a member doesn't affect your ad accounts in any way. It only ends their access.