To add or remove points in Adze, activate the Edit Point tool by choosing it from the Tools menu or by pressing P.
To add a point inside an existing track segment, select the Edit Point tool and click near the segment where you would like the point inserted. Adze will insert a new point inside that segment. Before releasing the mouse button, you can drag it to a new location (this is useful if you want to place the point some distance from the segment it intersects). You can always move the point later if necessary.
To extend an existing track by adding a point to the end, hold Shift and click near the end of the track you wish to extend. Adze will add a point to the closest end of the closest track.
To remove a point from a track, hold Option and move the mouse near the point you wish to remove. A small red crosshair will indicate which point is going to be removed. Click the mouse to remove the point.