Hello friends,

How To Change URL That Displays In Google's Results?

You can do 301 redirect of that URL to the url you want to keep at the same time you can send that new url to google bot with the help of webmaster tool.

The only way to address this properly is for Google to add <link rel="canonical"> to Google Sites so that Google Search knows which is the preferred URL.

For redirecting you can use 301 redirection. 301 redirect is the most efficient and Search Engine Friendly method for webpage redirection. It's not that hard to implement and it should preserve your search engine rankings for that particular page. If you have to change file names or move pages around, it's the safest option. The code "301" is interpreted as "moved permanently".