there is an easy way for adding or changing keyboard shortcuts to lightroom, for example ⎇ cmd N for adding a new collection set.
Go to System Preferences > Keyboard > Keyboard Shortcuts > Application Shortcuts hit + and add lightrrom. Type the name of the menu item (if it ends with three dots add those too) and type the preferred shortcut. It then is immediately added to lightroom.
Alternatively you can use the plugin Keyboard tamer at http://photographers-toolbox.com/products/keyboardtamer.php
I hope this helps