alt-left click on Tree lab icon, release mouse button before alt key. The Open pop-up modal is displayed listing all the tree presets. Select and open tree. If you release alt first or at same time as mouse button, the default tree is generated. Select tree you wish to save. Press ctrl-left on Tree Lab icon, again release mouse button before ctrl key. The Save As pop-up modal is displayed. Name tree and save. Import it as above.