How to update kubernetes from v1.8.5 to v1.8.6


Currntly, I am I hitted some azure disk issues while running kubernetes v1.8.5 on Rancher v.6.14. I would like to upgrade kubernetes to v.1.8.6. However, it seems the only way is through the page “kubernetes > Infrastructure stack” and click the “up to date” button. It only show one template version “v1.8.5-rancher4 (current)”. Is there any other way upgrade to v1.8.6