Note that this document is applicable to all versions until 12.8 included as the mentioned feature "/iam/sitemindermanage" won't be available in the next versions.
By default SiteMinder Administrative UI is configured for HTTPS connection. If for any reason you want to enable non SSL connection, then you can follow below steps :
http://<servername>:8080/iam/siteminder
http://<servername>:8080/iam/siteminder/adminui
Note : In case of R12.52SP2 Administrative UI install, the web.xml is located at following directory:
<Adminui_install_dir>\standalone\deployments\iam_siteminder.ear\management_console.war\WEB-INF