Select the page that you wish to edit, and click the "Edit" tab. You may notice that on the edit page, you can see the node number. When you create a page, its initial URL will always be www.yourdomain.com/node/##. This page was Node 35, so that is what the original link is.
Scroll down to the bottom of the page and select "URL path settings."
Type in the text that you wish to show up at the end of the url. For example, you may want your Services page to link to www.yourdomain.com/services.
If you're changing the URL path settings for a sub-page or drop-down page, you might include the mother page in the url. For example, your Attract Visitors page that falls under "Services" might be labeled www.yourdomain.com/services/attract-visitors.
Save all changes before navigating away from this page.