How can I re-insert a paper guide that came out of my LaserJet printer's feeder tray?

I have an HP LaserJet multifunction printer. It has two paper trays: Tray 1 is really just a door on the front that folds out and allows you to manually feed in sheets of varying sizes, while Tray 2 is the normal drawer that you fill with paper. And I have an unusual problem with Tray 1. The door has two plastic paper guides, which are adjustable grey tabs that move in unison. So when you widen the paper guide on the right side, the left one moves the same amount in the other direction. My problem is that one of these paper guides, along with another plastic piece that accompanies it, came loo

Question by soapergem on Super User, licensed CC BY-SA. We show a short excerpt and link to the original thread as credit.