With this new version of CWR², the download is split into 7 parts to make life a bit easier for people with weak connections. It also makes updating the Mod easier because not the whole thing must be uploaded when only one pbo has changed.
The installation remains the same, only that you now must extract 7 archives instead just one.
For the Expansions and additional terrains, get back to the downloads page.
For the Campaigns and missions, see this page.
For patches and hotfixes, see this Google Drive folder.