@willthom
Thank you for posting on HP Forums,
Riddle_Decipher is at your service.
As I understand you need help closing the extended tray for paper support,
No worries, as I'll be glad to help you, that said, I'll need a few more details to dissect your concern & provide an accurate solution:
Did you try closing it in a swivel direction towards the left/right?
Look at the image below for details on how its opened:

CLICK HERE FOR MORE STEPS AND INSTRUCTIONS Page. 26,
(By the end of this article all the issues should be resolved)
Let me know how that pans out
feel free to give me a virtual high-five by clicking the 'Thumbs Up' icon,
followed by clicking on 'Accepted as Solution' as it would help the community gain more knowledge,
And Have a great day Ahead!
Riddle_Decipher
I am an HP Employee