Not sure why this question has come back to the top of the list. Assuming someone is still after an answer:
You can't. Unless the remote site specifically sends
CORS headers[
^] to indicate that your site is allowed to access its data, cross-domain requests are blocked for security reasons.
Your only option is to create a server-side proxy endpoint. The Javascript on your site calls a server-side script hosted on your site, which loads the page from the remote site on your server and returns the relevant data to your Javascript.
How you do that will depend on which server-side language you are using, which wasn't part of your question.