This method won't reset the configuration.
During the boot process, you rename the current configuration so it doesn't get loaded.
rename flash:config.text flash:config.old
When the switch boots, it loads a blank image. Then you rename the config file and load it into the running config and you can change the logon credentials to something you know.
It's important that you follow the steps exactly so you don't lose the configuration. Password recovery is a pretty common procedure.
The only other method of recovery is if you have a copy of the current running configuration. Send me a private message if you have this config and we can discuss the possibility.
