I have never owned a MAC PC and a friend of mine has one (we live in different States). Anyway, I'm trying to talk her through installing Calibre plugins. First of all since she has Calibre for MAC installed, I'm stuck at this step: After going to Preferences, And Clicking the Green Plugins tab, she did not have File type plugins!

Could someone tell me how to install plugins on a MAC so I can walk her through it?
She also said she did not have “Load plugin from File” button since I told her to skip the File type plugins and just click the “Load plugin from File” button to install the plugins?