How to insert the ClickPad buttons back (on X1 Carbon)

Hi, I took out the left and right buttons at the top of the TouchPad, and now I am having trouble inserting them back correctly. Can I get some tips how to do that?

I've tried couple techniques, but I either end up with a button that requires a lot of pressure to click, or with a button that only works on the bottom end.

As far as I can tell, nothing is broken - it just needs to be inserted properly. How??

Thanks for tips!