If you don't have it, download and install the Chrome web browser.
Login to Netflix via the Chrome browser.
Go to
netflixparty.com and install the extension.
By signing up with this form, you will receive an email 30 minutes prior to the movie screening with a link to the screening
As you join via the link you will see the chat window at the right.
Click the icon in the top right (probably popcorn or a hamburger, etc) to change your nickname and avatar. The screening will start at 6PM. You will see a paused screen until the movie starts.