On the tab for the workspace, click 
Menu and select Delete Workspace, orNote: | If you just want to temporarily close a workspace because you do not need it open, see Closing Workspaces. |
Note: | To delete a workspace, you must either be the owner of the workspace, or if you are using a workspace that another user has shared with you, you must have “Full Control” permissions for the workspace. For more information about sharing workspaces, see Sharing Workspaces. |
On the tab for the workspace, click Menu and select Delete Workspace, orOn the Navigate tab of the navigation pane, right click the workspace name and select Delete Workspace.