By selecting a library in the 'Library Repository' dialog (menu 'Tools>Library Repository') and exporting it via the new <Export> button.
By selecting a library in the Library Manager and exporting it via the context menu command 'Export library' (right mouse button). If necessary, you can add this command to the context menu using the menu command 'Tools>Customize'.
Exported libraries can be installed via the 'Library Repository' dialog.