I'd like to disable the alt+rightclik keybinding as it is shared by Blender. All of the solutions so far have involved using ccsm, but so far, that hasn't worked for me. Does anybody know how to do this?
After a bit of research following Fabby's comment - I used the following command, which has worked:
gsettings set org.gnome.desktop.wm.preferences mouse-button-modifier '<Super>'
Now it's the super key which brings up the window menu.