To delete groups and their content, in the menu select **Modification -> Remove -> Delete groups with Contents** and select one or several groups you wish to delete in the 3D viewer or in the Object Browser.
The selected groups will be listed in **Delete groups with contents** menu.
Then click **Apply and Close** button to remove the selected groups and close the menu or **Apply** button to remove them and proceed with the selection.
..note:: This operation removes groups **with their elements**. To delete a group and leave its elements intact, right-click on the group in the Object Browser and select **Delete** in the pop-up menu or select the group and choose **Edit -> Delete** in the main menu.