To Modify a Dimension Style (AutoCAD Mechanical Toolset)

1. At the Command prompt, enter AMOPTIONS.
2. In the Options dialog box, click the AM:Standards tab.
3. In the Standard Elements list, double-click Dimension. The Dimension Settings dialog box appears.
4. Click Edit. The Edit Dimension Styles dialog box appears.
5. Select the type of dimension (substyle) to change and click Modify.
6. In the displayed dialog box, make the necessary changes and click OK until all dialog boxes close.