He who is Oren said on Sun, 19 Nov 2017 13:04:06 -0800:

The last link to the "clips" puzzled me. They look like those do-dads
on the end of a wagon axle (G).

It turns out you have to remove the entire rear shelf, flip it upside down,
drill out the heated melted posts of the speaker grill which are
permanently attaqched.

Once you drill out the old posts, you then insert the new posts using the
metal clips (which comes in the speaker grill parts bag from the dealer).
https://youtu.be/Ve-kcKxbXx4?t=575