Created a Site Collection under wrong Managed Path? Now want to move the site collection to another managed path? Unfortunately there is no way, other than:
- Backup your source site collection
- Delete the source site collection
- Restore the site collection with the desired target URL!
There is no other way to change managed path for SharePoint site collection. These steps also applies If you want to rename Site collection URL. This can be done with either STSADM or with PowerShell.
For detailed step-by-step instructions see my post: How to Change Site Collection URL?