GENERAL procedures may vary on varying devices!
1. power off and back on the device
2. hold down control and hit BREAK (may have to do this a few times)
3. Once you are at the rommon> prompt, type confreg.
4. Say "n" to all options except this one:
enable "ignore system config info"? y/n [n]: y
5. Say "n" to all other options
6. once back at the rommon prompt, type reset
7. the device will reboot
8. Once the device is booted, you will know that you are bypassing the config because you will be asked this question (say no):
Would you like to enter the initial configuration dialog? [yes/no]: no
9. Once booted, if you do a show version, you will see that your config register is 0x2142.
10. Now, you can either go to enable mode and do a show startup-config to see what the enable password is OR, if you have an enable secret password set, you can replace it by doing a copy start run, then going into global configuration and creating a new enable secret with enable secret cisco, then copy it back with copy run start.
11. Now, you want to change the config register back. In global configuration, type config-register 0x2102
12. save your configuration with wr or copy run start
13. reboot the device and you should be back with your original configuration but with a password that you know!