I literally just did this last weekend on our SJ 66 fastback. It looks to be pretty close to the same as in Jeff's pictures. You're approaching things right, doing the top hooks first. The bottom part of the seat was a real bugger for me too. Always has been and it seems like I always forget how to do it because I don't do this everyday, for sure...maybe 4 times now over the span of 27 years...
I had to crawl back there, with the front seats all the way forward. Put my knees on the floorboard and facing square to the back seat bottom, pushed really hard down and back at the same time on the front/top area where your legs would overhang, if you were actually sitting down in it, and got the passenger side to finally hook up doing this. I've never been able to get the other one to hook, so it must be a bit tweaked in alignment or on that outside spring wire/support that you'll see and feel in there. It's not very easy though. I'm 200 lbs, 5'10" and it's work just to get myself scrunched back in there. Fastback rear seat areas were build for smaller people and/or kids in my humble opinion...! Good luck to you Angela!
-Lance