There are already a lot blog posts, but there was none carrying all parts together. So here the overview for all necessary changes.
- First follow the instruction of Travis (Link). This changes the detail pane on the right side of the portal.
- If you want to customize your language settings – or have an unsupported language, Anders Asp (Link) will help.
- In the next step you can customize the menu on the portals left side – found at Stefan Johner (Link).
- How to change the Header of the Website (Link)
- How to localize the date.
- Go to Site Actions, Site Settings, Regional Setting and change the local for the site.