CAD tip # 11967:

If some of these standards are changed subsequently and you need to update the existing, finished or partially finished drawings, you cannot just re-apply the template - the template is just a normal static initial drawing - but you can use the following two main approaches to perform the update.

1. Select the whole existing drawing content and copy it to the Clipboard. Open a new drawing based on the new template a paste your drawing from the Clipboard into it, on the original coordinates. Due to possible problems with layouts, with reactors, with locked, invisible and special AEC objects, we do not recommend this method.
2. The second option is using the Drawing Standards (DWS). Attach the new template with the STANDARDS command as a standard template and let AutoCAD automatically check any differences and violations of the new standards. We recommend to rename the DWT template file to the DWS extension, to keep it write-enabled and have it selectable in the Standards command dialog. In this way you can only update the supported drawing elements - layers, dimension styles, text styles, linetypes and any additional objects added to Standards as plugins.