How do I install more than one WordPress blog on EC2?

Unless EC2 is much different than other servers, you should be able to install another WordPress installation under another directory.

For instance, you could have /var/www/html/blog/ with WordPress installed and /var/www/html/blog/wordpress with another WordPress install.

You can either use a separate database or use the same one as the other install, but you would need a unique table prefix set in the wp-config.php.

You can read more about multiple installs here:

http://codex.wordpress.org/Installing_Multiple_Blogs

I’ve never used EC2, but I would assume it would work very similar to any other server. If not, you may want to reach out to their support to see what the differences are.