My b2evolution Version: 2.4.x

I would like to know what file that i would have to change in order to have my file manager, when uploading files user the owner and group that i chose for this blog instead of apache for owner and apache for group. Please help all i really need to know is where the file is and once i change it if there is anything that i need to do to put it into effect if the variables are stored in more than that one file.