how to install Kotlin 1.4.10-release-IJ2020.2-1 update offline?
What kind of installation do you mean?
Here’s some example of how I would update the IntelliJ plugin, Kotlin, and IntelliJ but all of them require you to be online.
For the Kotlin plugin:
IntelliJ should prompt you to update the Kotlin plugin-- Or you can go to settings → plugins and update it yourself.
For your project’s Kotlin version:
In your Gradle project, you should be able to simply update the version number in your build.gradle.
For IDE updates:
I use JetBrains Toolbox to auto-update IntelliJ.
And for command-line compilers, it depends on your platform.
(On my Mac, brew upgrade does the trick.)
If you want to install the Kotlin plugin for IntelliJ IDEA offline, without an internet connection, you can download it first from the plugin portal Kotlin - IntelliJ IDEs Plugin | Marketplace and then use “Install plugin from disk” IDEA action to install it.