Swap alt and super

I have a Macbook Air that runs Linux. I want to swap the alt and super keys in both sides of the keyboard with each other. How do I do this with cli tools? **Update** Following Drav Sloan's answer I used the following: keycode 64 = Alt_L keycode 133 = Super_L remove Mod1 = Alt_L remove Mod4 = Super_L add Mod1 = Super_L add Mod4 = Alt_L keycode 108 = Alt_R keycode 134 = Super_R remove Mod1 = Alt_R remove Mod4 = Super_R add Mod1 = Super_R add Mod4 = Alt_R