1. Add necessary class (.lrm-login or .lrm-register) to <button>, <a> or menu item.
2. If you wish to hide Login/Registration link when user is logged in - add class .lrm-hide-if-logged-in.
3. If you wish to display any link, like "My Cabinet" only when user is logged in - add class .lrm-show-if-logged-in.

That's all! Easy, is not it?