Sharepoint - How can I change URL of existing list?

You can change the URL of a SharePoint 2013 List in Designer by following the steps outlined in this SO post:

Change SharePoint Library URL

Essentially: In SharePoint Designer just navigate to All Files navigation node (not List and Libraries node), find your list there -> right-click list -> rename.

The URI would change then.

Using Powershall Script , change list URL.

Add-PSSnapin Microsoft.SharePoint.PowerShell –erroraction SilentlyContinue

$libOriginalUrl = "/Lists/YourLibName1";
$libNewUrl = "/YourLibName2";
$web = Get-SPWeb -Identity http://....

$lib = $web.GetList($web.Url + $libOriginalUrl)
$rootFolder = $lib.RootFolder;
$rootFolder.MoveTo($web.Url + $libNewUrl)

Yes you can rename the URL really easily. If you open up the list in Windows Explorer you can then just renmame the folder that represents the link. In the lists themselves is no possibility to directly go to the list, however you can pass by a library to open explorer and follow the tree!