There are several ways to edit a model. From the dashboard, simply hover over your model in the model list (located on the right side of your screen), click the blue "Actions" button, and select "Edit". The edit portfolio frame will appear in which you can edit your model. 

If you are on your model Risk Profile, locate the blue "Edit Portfolio" button in the top left side of your screen. A frame will appear in which you can edit your model.