Connect the ribbon cable to the notebook?

si
1

I dismantled my old laptop because it was dusty and was extremely hot. Now I want to assemble it again but unfortunately I have no idea how to get the fastener for the ribbon cable open. (see photo) unfortunately the thing is so antique. The typical pushing open / unfolding does not work here.

Connect the ribbon cable to the notebook
mi

Should just be plugged in…