•In the Browser, go to the "Stack" category.
•Select the stack to delete.
•Either do a right click on it, the "Delete" function is displayed, or click on the "Trash can" icon 
available at the right side of the Browser.
A message to confirm the deletion is displayed. Click on "Yes" to confirm the deletion or "No" to cancel the action.
Attention : it is not possible to delete a stack with the RTB validation (you must remove the validation first).