How do I put the headliner back together?

[Jinnai]

The back of the headliner of my 1988 Accord LXi hatchback was pulled off to access the hatchback bolts, and now I'm wondering, how was this ever put together in the first place? I'm confused, unless the entire headliner was supposed to be removed to access the liftgate bolts, which was not mentioned in the manual. The manual only says "lower the rear of the headliner" and then "Reinstall in the reverse order". How could I have lowered the rear of the headliner with this thing clipping it to the metal of the roof, and how can I get this thing back onto the headliner?
https://i.imgur.com/rjQspWr.jpg
https://i.imgur.com/32CC9aj.jpg

[ShiRen]

You probably did exactly what the manual wanted, pull the clip off and drop the headliner a bit. That trim piece just has to clip back into place correctly. I don't know the direction it goes on, but the metal clips slip over something, probably that particle board stuff above the headliner... this is probably going to be extremely finicky, nothing is as strong as it used to be.