Rinominare WebAPP:

$webname = Get-SPWebApplication | Where {$_.Name -match "SharePoint – 443 – B-Horses Portal"} 
$webname.Name = "SharePoint – 443 – Ettore Wine Portal"  
$webname.Update()

Rinominare URL:

Go to: Central Administration >> System Settings >> Configure alternate access mappings under Farm Management. Pick your web application and give a new URL to it.