URL name with underscore. How do I rename?

I'm new to SEO. I'm working on a site with url names contain underscore. I know it is not a good practice. How can I resolve the issue. There are many page urls contain underscore. How can I change the url into a SEO friendly one?

Thanks in advance!

 

I think you need to contact webmaster to do it. It was implemented in code or at back-end.

 

Hi,
It is advisable to create new SEO friendly URL and redirect old URL permanently( By 301 redirection method) to New URL.

 

Are you talking about your main domain? Or simply the internal pages? But either way, while dashes are accepted as the most SEO friendly, I have never seen any indication that it significantly impacts SEO. I am sure your time would be best spent working on other SEO issues.

 

I think you need to contact the webmaster to do it. It was executed in code or at the back-end.

 

Underscore is not a good practice in SEO point of view you should use (-) if you want good result in SERPs.