While I haven't the slightest as to how yours is attached, there's usually methods, screws and glue. see if it has nuts on the back that can be tightened. If that doesn't work, some 3m tape or jb-weld may be in order.
Most badges and emblems are attached with the 3M double sided molding tape. If it is loose, I would just pull it off and get some 3M molding tape at any auto parts store and replace it. Be sure to clean both surfaces thoroughly B4 replacing the tape.