cannot build in Android Studio because of Gradle version

Hi
I get this error

Gradle sync failed: Support for builds using Gradle versions older than 2.6 was removed in tooling API version 5.0. You are currently using Gradle version 2.2.1. You should upgrade your Gradle build to use Gradle 2.6 or later.

But I have no idea how to upgrade it the gradle website appears to be a practical joke