Help with EC2 Module

Hello Ansible pro’s, I am new to the tool and looking to solve a use case. I would like to complete a basic rolling update for our site, basically I want to deregister a web from an EC2 ELB, do some updates, then add it back in. I have been struggling with the playbook for this

I have a simple inventory file, it identifies one host under the [web] section. I also defined a variables file, I set the EC2 access and key, I then have the following .yml file: