There are two-
1. (easy, might not work of your bootloader's fried)- plug in the power adapter on the IT, then plug in USB, then power on.

2. (Emedded system olympics)- Cold flash the device. Requires specialized interface(usb->serial+hardware to attach to pads on PCB under battery, and a linux computer to flash from. But will unf**k almost anything you can do to it software-wise.

Try #1 before you try to return it at least... If you can't return it, Nokia will cold-flash it for you...

Cheers,
kernelpanic