Hi,
Could you please explain your question in more detail?
If you don't have any of the details that you've set-up to login into your router there's no other way to log in without knowing them or resetting the device.
If the WAN MAC Address is the only thing that you have and you can only access the device remotely - RMS would be the easiest solution, but if it's not what you're looking for - I believe I can't help you.
EB.