Preparation materials: a pointed vise and a suitable wheel
One, with a pointed vise to the wheels and chairs pry open the interface, counterclockwise prying more labor-saving.
Second, if you can pry it down at once is best, if like the following did not pry well, then only to find the pivot point again for prying.
Three, clamp the top of the circle, the circle as a pivot point, continue to pry open.
Four, and then take a suitable wheel mounted. However, it is recommended to get a few extra spares at once, just in case.
fifth, load the wheel to turn clockwise, really can not be pressed into it, then sit on it, use your weight to press down.