Why would you bind WildFly onto a custom port? This is because you might have a different service running on the same IP:PORT (that is, another WildFly or JBoss instance, Tomcat, or GlassFish).
Just open your command line and launch your WildFly standalone instance as follows:
$ cd $WILDFLY_HOME $ ./bin/standalone.sh
Now you can change the port using either the Web Console or the CLI:
wildflyas the username and
cookbook.2015as the password.