aliberesco

Hi everybody, i have a problem with a front speaker because suddenly it started buzzing and I realized that the center part (the silver circle) is dislocated as the picture shows. I tried to put it in place with my figer's pressure but it seems like it had a spring or something and it returns to be misplaced. Do you know how to repair it? I'd like to know if it can be fitted again or do i have to take it to service. Thanks a lot for you help i appreciate it a lot. regards, Al