What you need to replace
2 x 0.2 inch (5 mm) hex wrenches (sold separately).
How to replace
1: Insert the hex wrench into the left and right grooves of the shaft.
2: Secure the left hand wrench and turn the shaft with the right hand wrench inside
Rigid and stowed shafts require force.
3: Take out the short shaft (male end), the long shaft (female end).
4:When you install the wheels, please insert 4mm spacer inside the caster
5:Put on the wheels you want to replace.
A trick is needed to pass through the long shaft (female side).
If the shaft does not pass through,
Fasten the spacers between the bearings with a wrench.
6: Add 4mm spacer on the other side equally.
7: Hold the shaft in place with the left hand wrench, and tighten it with the right hand wrench to adjust the shaft.
Be careful not to overtighten the shaft.
The trick is to tighten while adjusting to a degree that does not loose.
8: Turn the wheel lightly by hand and turn it smoothly, and the replacement is complete.