Same with my model @sara Caruso. The six of them, and the two to release the keyboard, are shorter than the 18. All the screws had blue locktite on them.

I watched several videos, many of which had the action hidden behind the keyboard. The larger ribbon pulls out of the strip after the two white clips on the end are moved. The smaller one has a black strip which lifts from the ribbon side, releasing the cable.

It would be helpful to have more info on how to remove the two cables. The larger one has a couple of clips that slide, but what exactly comes off? Do the plastic strips lift, or do the flat cables just pull out of them? Don't want to break something!

The two clips push toward the space-bar part of the keyboard. There are further clips around the edge of the keyboard, but it can be removed by careful prying with a thin blade screwdriver.