To move an trunk from one group to another, locate it the directory, click on it and and drag it across towards the Trunk Groups panel. Whilst still holding down your left mouse button, position the mouse pointer on top of the group you want to move the trunk into, until it is highlighted. Release the mouse button to drop the trunk into this group. The focus will remain with the group from which the trunk was moved, to assist you when moving more than one trunk.
To move another trunk, follow the same procedure. Click on the group you have moved the trunk into and this should be displayed in the Trunk Groups panel. Click on the button to apply the new configuration.
In the example below, trunk 512 was moved from the New Trunks group to the Main ISDN group.