To modify an existing build source:
In the navigation pane of the Build Management tab, locate and select the build configuration containing the source you want to modify.
Make sure the build configuration is checked out.
Expand the build configuration until the Build Targets entry is visible in the project tree. This will also cause the Sources section to appear in the content pane.
In the content pane, click the Sources title to make it active.
Click the Edit Selected Object icon (shaped like a pencil). The Edit Source dialog box appears.
For File Name or Mask revise the filename of the source file, or the mask specifying wildcards.
For Relative path enter or revise a path to the source that is relative to the project relative path. This restricts the path to the sub-directory that you specify. For example, if the project relative path is C:\Projects\Qlarius\Java and you specify a relative path of Utilities, the path to the source will be restricted to C:\Projects\Qlarius\Java\Utilities.
For Build Type enter an item format. For details see Using Item Formats to Control Build Rules.
Click OK. The edited source appears in the Sources section.