These steps apply to data schemas, cohorts, models, and model versions. To delete a version, make sure you are on the page containing the original object with the version you would like to delete. In the box where your original object is, there should be a row for each version. Navigate to the version you would like to delete and select the three-dot menu button, shown here below:
The menu button is on the right-hand side of the row, click it to view a new menu. The new menu should have an option to remove that object's version, click on that to delete the object's version. To completely remove an object repeat the process to delete all versions, once the last version has been deleted the object will be deleted.
In the case of a project or a collaborator, there is no concept of a version so you will just navigate to the object and then select the three-dot menu button and choose the remove button from the menu.
Deleting a Version or Object in Every Interface within the Rhino FCP UI
Below is a GIF showing all the interfaces within the Rhino FCP application where you can delete an object. It displays the Projects, Collaborators, Data Schemas, Cohorts, Models, and Model Results pages and the Remove, Remove, Remove schema, Remove cohort, Remoce model, and Remove model result buttons, respectively. You will select one of the buttons to remove a project, collaborator, data schema or version, cohort or version, model or version, or model result or version.