Reconnect the power to the switch, and press CTRL-U during boot up.
At this point you should receive a password prompt. The password should be mercury. Note, there is a delayed response from the console.
You should now see a list of config and operation files. Look for the config file that has a 1 next to it in the S/UP field – this will be the config file that is loading with the bad/unknown password. Press “D” to delete a file, type the name of the file, it is case sensitive, so type the filename as it is displayed. The deletion can takes about 30 seconds to complete.
Press “Q” to quit, if no startup file is set it will default back to the factory default configuration.
If it worked, the login will be back to Username: admin and Password: admin, as the default login.