https://www.terraform.io/downloads.html

1. Change "YOUR_KEY_NAME_HERE" to your ssh keyname (assumes it's already uploaded)
2. Update the AWS region as desired (make sure your ssh key is in this region)
3. Add your AWS "access key" and "aws_secret_key" to this file (NOT RECOMENDED). Terraform will use ~/.aws/credentials if not specified in the .tf file. (RECOMENDED)

1. Run terraform init
2. Run terraform plan
3. Run terraform apply

If your IP Address changes, and you lose access to ssh into your hosts, just run terraform apply again and the security group will be updated with your new IP Address.

If you don't know how to create and upload a key pair to aws, see here. https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/ec2-key-pairs.html

1. Run terraform destroy