Installing the latest version of Nessus on Kali Linux 2018.2 or later is extremely easy.
Start by visiting the Nessus Home and registering for the Home version of Nessus. Be aware that the Home version of Nessus can only scan 16 IP addresses at a time. It is safe to give your email address to Tenable, they are very good about not sending you emails unless you specifically sign up for them
Download the version for Debian 6, 7, 8, 9 / Kali Linux 1, 2017.3, either the 32bit or 64bit version, whichever works for you.
One it is downloaded, run the command dpkg -i Nessus-7.1.1-debian6amd64.deb (File name will changed depending on version) which will install Nessus.
After that, run the command sudo/etc/init.d/nessusd start which will start the Nessus daemon
Once the install has completed and the Nessus daemon has started, use Firefox or your favorite browser and go to http://localhost:8834 to access your Nessus installation.
Create a user for yourself and then paste in the registration code that the Tenable team sent via email.
Nessus will then start downloading the updated scan information, be aware that this can take some time depending on your connection.