1) Enter the Shwifty Swamp area with one friend. Go inside the small hillside house.
2) Go to the metal bookshelf in the back.
3) Push up against the left side of the bookshelf until it is past the Ameer painting on the wall.
4) Go to the area the bookshelf used to be and smash the wall with your multitool.
5) Enter the secret room and grab the Token of Byron from it's pedestal.
6) Travel to the resting place of the 9 sages in the Waleed temple (located in the east of the Greeny Grasslands area) with your friend. Stand in the middle of the surrounding sage statues (on the stone platform).
7) Take out the Token of Byron and hold it in the sky.
8) Have your friend take a picture.

You should now get an achievement and the "Garbs of Vincent" set is now available for purchase in Bree's Market for 8,000 ruby tickets.