Click the join roof planesedit button then click on the bottom edge of the top roof plane to join to the selected edge of the first plane.
How to change hip roof to gable.
Using a stepladder remove all of the gutters roofing tiles and any other kind of roof furniture from the roof.
Click the join roof planes edit button.
Expose the wall beneath the roof.
Use the select objectstool to select the top edge of the bottom roof plane.
Click the ridge of the lower roof plane to join them together.
On the roofpanel of the wall specificationdialog select the full gable walloption then click okto close the dialog and apply the change.
Here is a quick video on how to change a hip to a gable and vice versa in applicads roof wizard software.
Click on the ridgeedge of the upper roof plane to select it.
In floor plan view click on a wall that you would like to form a gable over to select it then click on the open objectedit button.
In order to make the conversion you will have to remove part of the roof.
Decide where you want the gable part of the roof to go and mark this down on your plans.