Update my application over the internet.

I want to create updates for my game and would like to let the game to update themselves over the internet.
How should I do that?

This question is not directly related to Unity or to games in general. Implementing such an auto-updating feature is quite common problem in business applications as well. I suggest googling a bit - I’m sure you’ll find a lot of related info.

But to give an example - Blizzard uses a launcher for all its games. When you start it, updates are detected, downloaded and applied, and then you can start the game. Launcher developed by them is quite advanced (supports pausing download, allows you to play after downloading only crucial parts of update, etc.), but if you need something simple, you should be able to complete it quite quickly.