When a project is created, a name must be given to the project during creation. A project owner can update the project while the project status is Open or Overdue. If a project has a status of Closed or On Hold, the project title can not be edited.
The project title can be edited in the right side panel in the project's Info tab. Hover the mouse over the current project title until the edit icon appears. Click it to edit the project title, and hit or press enter to save changes.