I got the issue fixed. I was able to change the debug port number. Below are the steps
- Start the server in normal mode (ctrl+Alt+R).
- Go to application server configuration window.
- Click on Debugging service under "Additional properties"
- Update the JVM debug port e.g. 7780
- Update JVM debug arguments for address e.g. refer the address=7780 for the below entry
-Dcom.ibm.ws.classloader.j9enabled=true -agentlib:jdwp=transport=dt_socket,server=y,suspend=n,address=7780
- Click on apply
- Click on save
- Stop the server
- Start the server in debug mode (ctrl+Alt+D).