Alex, Peter and Brandon.
Thank you again for explanations. I think I got the idea.
I would request Coastal Route and wait for ATC response, I would either be allowed to start descending somewhere south of LAX or I would have to wait to finish the route at Vincent Thomas Bridge ( depending on Controller preferences).
At this point I would hear: "exiting Bravo airspace, resume own navigation, blah blah" and since the class B floor at this point wpuld be 8000', I could descend at will paying attention not to bust SLI class D airspace with ceiling of 2500'.
Brandon, I understand about not expecting vectors, I am VFR.
Please correct me if I am wrong in my understanding of the subject.
Cheers, AJ