997.1 spoiler light unit

[spinone]

Hi all I am looking for some advice. I got home yesterday to find the light unit hanging out of the rear spoiler. I can push it back into the spoiler, but there do not seem to be any clips to secure it. I am guessing that once it has come out, a part has fallen off onto the road. Can anyone tell me how the light unit is secured into the rear spoiler. thanks