Stuck on lip sync step: create symbol with all the mouths in it.

I am stuck on the lip sync step create a symbol with all the mouths in it. I have designed all the mouths but I can't figure out how to put them all into the same symbol. I've tried numerous tutorials but none seem to help. Here is the project: https://www.dropbox.com/sh/ptms5d93l29wpgb/AADq1IeKR_o5zaBi5ekjDrOJa?dl=0