Upgrade from 2.8.1 to 2.9

Hello ,
can you please help me on how to upgrade from 2.8.1 to 2.9 , looks like 2.8.1 is depricated and I don’t find how to upgrade to least stable version 2.9
Best regards,

You should follow the general instructions in this page and in particular the section for upgrading to 2.9.0.