How To Reset Your Router's Password

You would want to connect a PC to the console port.   Power cycle the router, break the boot sequence, and modify the configuration register.

Here is a video tutorial to walk you through it:

Here is the link for the password recovery process from Cisco:

http://www.ciscosystems.com/en/US/products/sw/iosswrel/ps1831/products_tech_note09186a00801746e6.shtml

Select the model you are doing password recovery for, and it will give the exact steps.

Password recovery is an important skill for the real world.