Hi Nima,
Beta upgrades are not supported, so what I'm doing is setting up a new instance with the release candidate. Note also RC2 is out. RC upgrades ARE supported.
If you don't mind not being supported, you can replace the b4 files (and include the new ones), taking care not to override any local changes. You can look at the upgrade docs to see how to do this.
I'm not sure about the best place to upgrade from the UI.
