Editing brush strokes
You can edit any brush stroke by choosing it from the Stroke gallery (as though you were applying it to a path) and then clicking the Object menu, pointing at Stroke , and clicking Edit Stroke Definition .
You can edit a stroke using all the same techniques as creating new strokes, including adjusting the stroke definition box, anchoring points, and repeating elements. After you edit a stroke, you can close the Edit Stroke Definition window by clicking the close box in the flip tab or clicking Close from the File menu. Expression Design will ask you to name the stroke and assign a category. If you don't change the stroke's name, the program asks you to confirm overwriting the original stroke file.