Pinned Searches can be managed much like your Sections. You can edit the label, the query, and the order. You can also remove Pinned Searches, or create new ones (see our best practices on creating pinned searches here).
To make edits you click the "Manage Pinned Searches" button to the left of the filters.
Once you've clicked into the editor you can edit the labels in the left column and edit the actual search queries to the right. Please make sure you are using the search syntax: tags:"......" for the query column as seen below.
For any questions or assistance with using pinned searches please contact firstname.lastname@example.org.