|Good luck with that!|
I ran into a router with DD-WRT on it and I was unable to remove it or replace it with another 3'd party firmware. You could try emailing the people who make DD-WRT and ask them about removing it. They're probably the only people who could help you do so.
It matters not how straight the gate,
How charged with punishments the scroll,
I am the master of my fate;
I am the captain of my soul.