"To get started with Kotlin, download the Android Studio 3.0 preview, open one of your existing Java files, and then choose “Convert Java File to Kotlin File” in the Code menu."
You do not have to install a preview version of Android Studio, you can install the kotlin plugin in whatever version of AS you're using now. The change in AS 3.0 is simply that it will ship the plugin by default.
You do not have to install a preview version of Android Studio, you can install the kotlin plugin in whatever version of AS you're using now. The change in AS 3.0 is simply that it will ship the plugin by default.