In SMESH you can change the location of any node of your mesh. In this case all adjacent elements (edges) will be also transformed right after the displaced node.
To displace a node:
1. From the Modification menu choose the Move node item or click button in the toolbar. The following dialog box shall appear:
2. Enter the ID of the required node in the Node ID field or select this node in the 3D viewer. The coordinates of your node will be automatically displayed in the Coordinates set of fields.
3. Set new coordinates for your node in the Coordinates set of fields.
4. Click the Apply or OK button.