Rotate wheels to increase durability
Necessary tool: an allen key or a skater-tool.
With normal use, your wheels will always be worn more on the inside of the frame than on the outside. In order to get the most value from your wheels, it is important to rotate the wheels every so often. Otherwise, you will have to replace your wheels a lot earlier than necessary.
So. When is it time to rotate the wheels on your roller skates? The simple answer is: When one or more wheels is clearly more worn out on the tear-side.
Since your wheels are worn down in different paces, it's important to rotate them the right way. You could just turn the wheel and place it in the same position in the frame, but this will result in an uneven overall tear on the wheel. The result will - again - be that you will have to replace your wheels a lot earlier than otherwise necessary.
So, let's get to it.
Put the tool in the screw and unscrew it (for some skates a second wrench is needed to holding the axle on the other side of the wheel).
Remove the screw, axle and wheel.
Since you have full access to the frame, it's a good idea to clean the frame and the bearings. Check out this guide on how to properly clean your bearings.
If your skates have three wheels on each frame, the rotation should be carried out as illustrated above. Don't forget to fit the wheels so that the "old" insides now becomes the outside and vice versa.
If your skates have four wheels on each frame, you should do the rotation as shown above. Don't forget to fit the wheels so that the "old" insides now becomes the outside and vice versa.
Take notice: When the wheels have been rotated, the point of balance has shifted, so be cautious the first time you use them after a wheel rotation.