SIPStation and FAXStation

Log into the SIPStation store at https://sipstation.com
Click on the My Account tab at the top
Click on the Trunk Groups tab
From here we can see a list of all Trunk Groups for this location
From here you can press the Delete button next to the Trunk Group you want to delete
The default trunk group noted above can never be deleted. Any new DIDs that are purchased will automatically route to this trunk group and if other trunk groups are deleted, their DIDs will revert to routing to this default group unless those DIDs are subsequently moved to another trunk group.

SIPStation and FAXStation - Deleting Trunk Group