Change /wp-admin path

wp-admin unlike other WordPress sub-directories, such as wp-content and (sort of, wp-includes) is hard-coded everywhere, so you would need to use sed or some other such tool and recursively replace throughout WordPress core files every instance with the directory name you want.

You can install this plugin which allows you to create a blank page, and then when the user clicks on that link have it redirect them to whatever URL you specify. It’s not as proper as I’d like, but a clean, relatively simple solution if you’re not a programmer.