For all you achievement hunters out there looking to rack up your gamerscore, here's another video that may help you on your quest. If you've played any of the Skate series, you already know how awesome the game can be to play. In this tutorial, you'll be finding out how to get the Extreme Grindage achievement in their latest version, Skate 3. To get it, all you have to do is perform a 100 meter or 300 foot grind and boom, 10 gamer points are yours. So check it out and enjoy!