There are many times with Identity Manager where you need to make a change to a setting via an xml file or an .properties file in the iam_im.ear directory. This is difficult in many WebSphere deployments, as it requires a repackage and redeploy of the application.
You can implement hot deployment for WebSphere to get around this problem. This is not typical for production deployments of WAS, but is generally used with development and QA environments.
Identity Manager WebSphere 8.5.5
Per the documenation here: https://www.ibm.com/support/knowledgecenter/SSAW57_8.5.5/com.ibm.websphere.nd.multiplatform.doc/ae/urun_rapp_classload.html
Logon to the WebSphere Application Server Management Console and navigate here:
Applications > Application Types > WebSphere enterprise applications > application_name > Class loading and update detection
Select Override class reloading settings Set Polling interval for updated files. This is in seconds.
Submit changes and restart the iam_im.ear application
Now you can modify the settings and files in this directory to have them take effect: