Removing the Apple Adjustable Keyboard ribbon cable?

[penrose]

I'm currently trying to do a restoration on an Apple Adjustable Keyboard, and while most of the casing was fairly clear to disassemble, I'm at a loss as to how to disconnect the ribbon cable connecting the left and right halves. The housing the ribbon cable plugs to has no apparent latch, but even when pulling strongly or trying to wiggle, it won't budge. When I pull a bit harder the white housing that's soldered to the board moves a little, which definitely feels wrong.

Anyone know how to disconnect this thing without breaking the keyboard?

Edit: Just realized the title here was wrong. It's an Apple Adjustable keyboard, not Extended.

[penrose]

Just realized that the title may have been misleading, preventing the right folks from seeing the question. I've now edited the title to indicate that this is an Apple Adjustable Keyboard, not an Extended Keyboard.