There are two main ways to change the port in the Embedded Tomcat in a Spring Boot Application.
Modify application.properties
First you can try the application.properties file in the /resources folder:
server.port = 8090
Modify a VM option
The second way, if you want to avoid modifying any files and checking in something that you only need on your local, you can use a vm arg:
Go to Run -> Edit Configurations -> VM options
-Dserver.port=8090
Additionally, if you need more information you can view the following blog post here: Changing the port on a Spring Boot Application