MP Starscream: What's wrong with my head?

Long time lurker, now a new recruit with a Masterpiece problem that I'm hoping someone can help me with.
My wife just bought me MP Starscream (as you can tell by the title). Awesome toy - I love it but what's wrong is that I can't get the head to move back into position when I try to get him back into Jet-Mode. It's that small piece of plastic that sits right behind his head and I can't get the head to fit back through it.
Getting his head through so I can get him into bot-mode was tough the first time, and the instructions don't really cover this part. Can someone shed some light here on what it is I am missing?
Thanks.
My wife just bought me MP Starscream (as you can tell by the title). Awesome toy - I love it but what's wrong is that I can't get the head to move back into position when I try to get him back into Jet-Mode. It's that small piece of plastic that sits right behind his head and I can't get the head to fit back through it.
Getting his head through so I can get him into bot-mode was tough the first time, and the instructions don't really cover this part. Can someone shed some light here on what it is I am missing?
Thanks.