Exporting and Importing Themes 
You use the Theme Archive tool to import and export themes as compressed files.
Choose .
Your custom themes are listed under Export Themes.
To export a theme, choose the theme to be exported and specify a target folder for the compressed file.
To import a theme:
Specify the path to the theme that you want to import, or choose Browse to select the compressed file of a theme.
If you want the imported theme to overwrite existing themes, select Overwrite Existing Theme.
Choose Import.