Download a stock Rom.
Extract the contents of the .exe file to a folder on your pc using winzip.
Rename RUU_signed.nbh to LEOIMG.nbh and copy it to the ROOT of your storage card (preferably 2GB or lower).
Restart the phone while holding down the 'volume down' button to enter bootloader mode.
If the phone recognises the nbh file on your phone then it will give you instructions on how to flash it and then everything will go back to a stock state for return purposes.
Mark.
i have similiar problem. my usb port is broke and need to return. when i transfer the ruu signed.nbh file to sd card and change name to leoimg.nbh. then power up the phone with volume button down, the tricolor screen comes on and for a milisecond the gray screen comes up but then reverts back to tricolor and nothing happens. i have tried 2 different 16 gb cards with same results, i have even tried it on 2 different hd2s. maybe its the stock rom i am using to get the file from. can you post link to a known working stock rom. any suggestions would be greatly appreciated.