Download Zotero and associated plug-ins using these links:
Download and install Zotero Standalone from the Zotero website. Firefox users may want to install Zotero for Firefox, which lets you capture and organize all your research without ever leaving the browser.
(There's a different version for each operating system: Windows, Mac or Linux.)
Connectors allow your web browser to save citations to your Zotero library.
Open Chrome, Safari, or Firefox and click the Zotero Connector link for that browser to install it.
Each browser has its own version of the Zotero connector, so if you use multiple browers you'll need to install each connector.
Setup your Word or LibreOffice to cite Zotero items. Word processor plugins for Zotero Standalone can be installed from the Cite pane of the Zotero preferences.
Zotero for Firefox users will need to download the word processor plugin.