The following is a detailed guide on how to repair the durability of rune stones in Fantasy Westward Journey:

First of all, we need to understand that rune stones are actually disposable items. When the runestone's durability is used up, its combined effect will become invalid, and the only solution at this time is to replace it. You need to replace the equipment with runestones of the same color.

The way to replace runestones is to drag the newly activated runestones to the location of the runestones you wish to replace. After you place the new runestones, click the Inlay button, and then click "Yes" in the pop-up prompt box to confirm. At this time, the old runestones will disappear and the new runestones will take effect. This process does not need to wait until the durability of the runestone reaches 0. Inlaying runestones of the same type can increase the durability of new runestones on the basis of the original durability.
- After opening the game, select an activated runestone with the same color as the runestone whose durability has been exhausted.
- Hold down the shift key on the keyboard and right-click the mouse to equip the runestone.
- Drag the activated runestones into the runestone box to cover the runestones with exhausted durability.
- After confirming the replacement, click the Inlay button.
The above are the steps on how to repair the durability of rune stones in Fantasy Westward Journey. I hope this information can be helpful to you.