Linux Mint Forums

You need to install the emerald theme manager. The "appearance settings" is for gtk/metacity themes.

Open up synaptic and search for emerald. This will give you the "emerald theme manager" option in your menu (you might need to reload the pluggins on the menu to see it).
Open up CompizConfig Settings manager (Terminal command = ccsm).
Under "effects" click on "Window Decoration" and change /usr/bin/compiz-decorator to /usr/bin/emerald
Log out and in again.

You'll have to reverse step 3 to switch back I think. I don't know as I don't actually use emerald themes.