I finally got this installed onto the linux server! Here is the exact command I inserted into the Putty command line:
aws iam upload-server-certificate --server-certificate-name mywebsitecert --certificate-body file:///home/ec2-user/mywebsite/mywebsitecert.pem --private-key file:///home/ec2-user/mywebsite/privatekey.pem --certificate-chain file:///home/ec2-user/mywebsite/interm_reverse.cer
I used InCommon SSL Certificates to complete this task.