Update from 2.0.2 to latest version (2.1.3)

[eluser]Unknown[/eluser]
Hi everyone,
I need to update from 2.0.2 to 2.1.3

What's is the procedure? I have to download all the intermediate versions and updates to step-by-step?
If I do this, where can I download all the latest versions? I find only the link to 2.1.3 .......

Thank you very much, any help will appreciate!

Giovanni Di Gregorio