Yes, but, after the first shot:

* Commit your bugfix / make a patch

* Send your patch to the maintainer of the project

* The maintainer has to look in a central file if you already assigned copyright to the FSF. Since you did, you don't have to do anything.

I'm confused though: Apple already have assigned copyright. Yet, they say they will stop doing it, as if it wasn't automatic, even when done once. Either they assign copyright in an unusual way, or they actively stopped it. Somebody knows which it could be?