@Dan82He means here on the forum.
Step one is: Send @a31632 an message here on the forum, There are some steps one of them is message him here on the forum in an private message, Then he will send you a link where you can donate to him for the skin. Then you will get the download link and the password.
This was a quick searching about how i did get it. You should send A31632 an private message for more information.