If you read all the way through this link, you will find everything you need: I've installed three of them now, and they are very simple. Note that '67 is different than '68-'69 regarding the latch and clip. As far as your question about the seat bottom, that mounts the same as the non fold down seat. Only the upper part is hinged and latched. There are dimples in the floor sheet metal that the hinges fit into, so not much concern about getting them in the right spots.
http://firstgenfirebird.org/forums/u...531#Post102531