The installation of Citadel consists of a number of moving parts: Citadel needs to be installed in the browser, on the OS, and in your SIEM. Nevertheless, installation of Citadel should be relatively straightforward. The the installer takes care of everything except integration into your SIEM. Everything is explained in the installation guide.
Also check out the configuration manual to understand how you can adapt Citadel to your organisation, for example by configuring your logo, name and support e-mail address.
And finally. Citadel takes great care to respect the privacy of your users. Nevertheless, the deployment of Citadel will undoubtedly raise various questions related to privacy compliance and internal communication. You will find in the privacy section some documents that will help you deal with those.