I Need help unrooting my device Device: HTC Inspire 4g.

My Device was having some hardware issues, so i complained to AT&amp;T and offered to send me a new device.  I have to now return my old device but it is ROOTED.  I do not want to send it back in this condition because I fear I will get caught and have to pay full price for the device.

My question is how should I go about unrooting this device.  I've seen many different forums and topics, but most of these methods are not working for me.

Install stock AT&amp;T Rom - Could not find the zip file anywhere on the internet.
I've tried using an RRU but my device cannot be detected by my PC.

If anybody can help me get either of these 2 methods to work, or come up with a new method it would be greatly appreciated.

Thank You
Check out this link that is what you want:HTC