First you need to have or create a Ubisoft Uplay account. If you don't already have one, pause the game by holding your left arm down at a 45 degree angle and scroll down through the options and you will find the Uplay menu. Select that to access the information on how to link your profile. Once Uplay loads, use a controller to toggle over to the Help tab on the left and select "Hints and Tips".
Now on your computer go to www.yourshapecenter.com and on the middle of the left side of the screen you should see a "Track Your Progress" banner. Click on that to sign in with your Uplay credentials. You do NOT need to sign up for Facebook to do this (unless you want too). Wait a moment and your page will sync with your gamertag profile and give you some stats.
Now return to the game and complete an event or activity (may need to complete more than one) and when the game saves, the achievement should unlock.