first you will need to buy a axial locker say for the axial wraith. then when you have it or them depending on weather or not you want to do just the center diff or the front and rear as well. you may need up to three lockers if you want to do the hole car. second remove the diff from the car and take it apart and remove the two c clips that hold two of the spider gears so that you can remove all four spider gears and the center shaft, put the hd locker in in place of all the small gears reinstall the larg ring gear and push the drive cups back in. you may need to twist them until the push in all the way. then just put the hole diff back in the car. I would take a pic but I would have to pull a diff out and well that's a lot of work. I have two lockers in my exo and its fast, blows great donuts and launches hard.