Question: how to change your minecraft version to 1.8?
Answer: Click the dropdown box for “Use version” and change it to “release 1.8.9”
Click save profile and you will now be running 1.8.9.
You can confirm if you are running 1.8.9 by looking at the version number on the lower right of your Minecraft Launcher. Make sure it says 1.8.9.