Is there any way to reset a 1841 to factory default settings?

How would I configure automatic ISDN backup on a 2841 if my T1 fails?

I have a CISCO 2811 with two (2) VWIC2-2MFT-T1/E1 cards. I am trying to configure them to use T1 for both ports. I ahve point-to-point T1's set up thgouth my telco provider. I am familiar with configuring frame-relay on CISCO 2500's but don't know...