If you are referring to customizing shortcuts as in Photoshop, but doing that for Lightroom, such customization is not available for Lightroom. If you are referring to something different then please be more specific.
Not as easy as in Photoshop, for one, but it gets the job done. I've used this method to change shortcuts that I use often but were not available on my non-English keyboard, as well as to reassign some letters to other actions.
Hope that helps,
Michael Niessen - Photographer, photo-editor, educator