I bought a new cardboard rear package tray for my 67 Coronet R/T to replace the factory one hacked up for speakers.

How do I remove the old one, and install the new one without damaging it? Do I need to remove the rear seatback?

Thanks!

Yep - remove rear seat.

And in case you've never done it before, seat bottom comes out before seat back.

Oops - I should have mentioned that part.

Thanks pals... I'm on it, Saturday morning!!

is the bottom seat held in via a spring latch type mechanisms as with some other brands (i.e., you need to push the lower front edge of the lower seat inward to disengage it from the latches at the front)?

And if '67 is the same as my '68, once the bottom seat is out, the seat back has two pull-out latches near the bottom of each side. Then it lifts up off some hooks toward the top.

In my experience getting it out is way easier then putting it all back together.