# Modifying an existing project

Modifying an existing Developer Studio project to match a new deployment template application is a somewhat tedious task. In fact, it is often easier to simply create a new deployment template application instead.

The important key is that the [appname].*.xml files share the same [appname] as the deployment template project. Since there are 30+ XML files, you can either:

- Rename each of the XML files with a new prefix, and update the [appname].esp file to reference each new file.
- Update the deployed application's AppConfig.xml file to specify the [appname] of your configuration files. For example, if your configuration files are named myapp.*.xml, update the configuration as follows:

        <app appName="myapp" eacHost="host1.company.com" eacPort="8888"
            dataPrefix="myapp" sslEnabled="false"
            lockManager="LockManager">
          <working-dir>C:\Endeca\apps\myapp</working-dir>
          <log-dir>./logs/baseline</log-dir>
        </app>

In most cases, the `appName` attribute and the `dataPrefix` attribute will be identical. However, this is not required and an application can be configured to support files with a data prefix other than the application name. If the data prefix is not specified, the application defaults to using the application name.

Note that opening an existing project in the Oracle Endeca Developer Studio and using the Save As feature will not rename the corresponding *.xml files. It will only rename the [appname].esp file. The prefix for the XML files can only be specified when a new project is created.

Related reference
Common errors