The structure of Building Blocks
Because of its XML format, the contents of a Building Block can be edited manually using any text editor or XML-authoring solution.
For example, if you have installed a new print server to replace an existing one, then all network printer settings in your environment need to point to the new server. Instead of editing each setting individually, create a Building Block of these settings. Open the XML file and replace all references to the old printer server with references to the new one. Finally, import the edited Building Block back into the Workspace Control site.
Modifying a Building Block may lead to unexpected results. Before you modify a Building Block, make sure you have created a backup.