Go to the navigation window (see image below).

Place your cursor in the field "Navigation tree" (see the first image below). When you do so, you will get access to an icon called "Open" (see the second image below).

3. Click "Open" (see the first image below). When you do so, the navigation tree you are working with will open. When a navigation tree opens, so does its navigation tree card (see the second image below). Via the navigation tree card you can work with the navigation tree settings and also remove a navigation tree from Pythagoras Web. For more information on how to work with the navigation tree settings, see section 5.6. in the manual for Buildings. For more information on how to remove a navigation tree from Pythagoras Web, see section 5.7. in the manual for Buildings. You will find it here.