That's rather incorrect to say that NGINX is better. If it were true would anybody still want to use Apache at all? And if you are unfamiliar with NGINX I would not recommend replacing Apache with NGINX on a live server. If you do so you most likely will have numerous issues with your sites and you might end with hating NGINX. NGINX does not support mod_php and does not support .htaccess, hence it does not support rewrite rules in Apache native format.
If you want to try NGINX either install it as a reverse proxy in front of Apache or use it on separate server. Check How-To subforum for guides on how to install NGINX as a reverse proxy.