A little backstory because context always matters. Kevan Brighting has had a long career doing voice work for various companies and business presentations. He has what he considers a "well modulated BBC voice" and began working on more mainstream projects later into his career. He had auditioned for The Stanley Parable through an ad on Voice123.com (horrible site name). Thinking it was something "religious" he accepted it anyway and found the story intriguing. Despite not being a gamer, he expressed interest in playing it at some point, but admits that he likes watching others play it. Since then, people have asked Kevan to do voice work on their games, but he refuses as he feels it would "dilute the effect" of The Stanley Parable.

What you need to do first is open the config.cfg with Notepad.
You then will need to pick the key you want to bind to a new command and bind the key to "~;_u"
Save the config file and make it read-only, as you are reading his guide. Same concept but with computers an other devils.
Start Stanley Parable up and go into the game.
Hit the key you bound to "~;_u" to unlock a static photo of Kevan Brighting. From there you may select from a range of dialog options until you finally get to the meat and fats of the tree.
Step 9- Have fun!