Override application.properties data through a rest controller end point in Spring Boot 2

Question

I want to have a RestController end point which can be used to override application.properties files.
Requirement: We have one spring boot application in which we want to override few properties using Rest end point.
We tried below way but this works only if we start application, but our requirement is even if application is running we should be able to override it :

java -jar spring-boot-1.0-SNAPSHOT.jar --spring.config.location=classpath:application.properties,/opt/somewhere/override.properties

Is it possible? if yes then what is best way to do this?