Change "Application is agent" to switch between Menu- and StandardApp

Hi all,

If I have a Menubar App I would set the “Application is agent (UIElement)” in the Info.plist of my project to YES.
For a standard Application it is NO.

I have a situation where I want to let the User decide if he/she wants to run the program in menubar mode or as a standar application.
I know (or at leat read) that I cant change the info.plist during runtime.

Is there any other way to do it?
I found an article with the exact same question but it doesnt really click for me if I read the answer…

Maybe someone can help out?

Thanks in advance.