You can use the Window Groups pane of Terminal to manage your window groups.
Window Group list
To delete a window group, select the window group in the list, and then click the Delete (-) button.
Action pop-up menu
The Action pop-up menu is located in the bottom-left corner of the preference window and looks like a gear.
To use window groups created on another system, choose Action menu > Import, and then select the Terminal settings file. The file name of the Terminal settings file usually ends with an extension of “.terminal”.
To export a window group so it can be used by another system, choose Action menu > Export, and then select the location to save the file