Click Draw path, then click waypoints on the map (either view). Drag a waypoint to move it, right-click it to delete it. In the 2D map, drag the small dot between two waypoints to insert one. Esc finishes drawing.
Click Set radar position, then click the location on the map (either view). Drag the marker to move it, right-click it to remove it. Drag the tip of the red boresight ray (either view) to point the radar; fine-tune under Antenna.