You can change the port your Unimus server runs on.
You can also change the server bind-address if neccessary.

On Windows:

For installer:
Create a file named Unimus.l4j.ini in 'C:\Program Files\Unimus\'.

For portable:
Create a file named Unimus.l4j.ini in the same directory as the Unimus executable.
Change Unimus in the above file name to exactly match the name of the Unimus executable.

Inside of this configuration file, please place the following lines:

-Dserver.address=<your_ip>
-Dserver.port=<port>

Please make sure to place each argument into its own line.
Insert proper values behind each configuration argument.

If you only want to configure a single parameter, please omit the other.

Restart Unimus, and the configuration should be applied.

On Linux (Debian/Ubuntu):

Edit the contents of /etc/default/unimus.
If the file doesn't exist, simply create it.

Insert this into the file:

-Dserver.address=<your_ip> -Dserver.port=<port>

Insert proper values behind each configuration argument.

If you only want to configure a single parameter, please omit the other.

Restart Unimus, and the configuration should be applied.

Running in Tomcat:

Please refer to Tomcat documentation on configuring server port and bind-address.

How this is configured depends on the distribution and packaging of your Tomcat.