Wiped USB by accident, can't reinstall

I followed the instructions and got my Piratebox working with no problems. Then, however, I accidentally wiped the USB. Now I can't connect with the box anymore. I can't telnet, I can't ssh, I can't open a web browser to 192.168.0.254. What should I do?
I have a TP-Link MR3020. The computer recognizes the connection when I connect the box via ethernet but that's all.

Thank you!