How can I redirect all http (non-secure port 80) requests to https (Secure port 443)

You can use the .htaccess method using mod_rewrite as follows

RewriteEngine on
RewriteCond %{SERVER_PORT} =80
RewriteRule ^(.*) https://%{SERVER_NAME}%{REQUEST_URI}

Any good webhost will have mod_rewrite installed and allow .htaccess files.