Things You'll Need
Instructions
Lay your yo-yo on its side and locate the hubstack wheel bearing post. The post is a small protrusion centered on the side of the yo-yo.
Place the wheel bearings onto the hubstack post. The bearings should slide right on without much effort.
Take the rubber o-ring from the hubstack assembly kit and slide it onto the post, over the wheel bearings. Gently press the o-ring until it sits directly on top of the wheel bearings.
Place the hubstack onto the hubstack post. Gently put the hubstack over the bearings and the o-ring and push down until the hubstack snaps into place. Use the least amount of pressure necessary to snap the hubstack in position to avoid breaking the hubstack or the hubstack post. Both of these pieces are delicate.
Spin the hubstack to ensure it spins freely. If so, flip the yo-yo to the other side and repeat steps 1 through 4. If not, remove the hubstack with a pair of pliers and inspect the assembly. You may have accidentally placed either the bearings or the o-ring in the wrong position.