Attaching the cover stitch plate

Question

I've just acquired a Juki MO 735 serger which I love beyond words. But I've never used a cover stitch before and cannot for the life of me figure out how to attach the extension plate! The manual diagram just isn't clear to me. Can you help? perhaps with an emailed photo? I've disengaged the looper,  raised the knife out of the way and removed the knife guard but can't get the d**n thing to fit any which way I turn it.

Thank you!