Maya 2012 Tutorial
How to Edit a Curve in Maya
Once you create a curve, you may need to re-shape it. To access the curve vertices you must be in the component mode. For more information about curves, see topics; Create CV Curve and Create EP Curve.
With a curve in the workspace, select the curve and click the Component Mode icon. You can also access the vertices by right clicking the object and selecting Control Vertex.
In the Component selection filter icons, click the Vertices icon. It should have a dark gray square if selected correctly.
Choose the Move tool. Click and move the various vertices to reshape the object.
When you have finished editing, click the Object Mode icon and the object is no longer in the component mode.