server 2000 password recovery

I have a server with windows server 2000 on it. I recently purchased this machine and the guy I bought off gave me the admin password. the only problem I can tell is that the server is not on their domain and the admin password doesn’t work I assume because of this. My question is, is there a way to log onto the server using the local admin and if I can is there a way to recover the local admin password. I want to keep the OS intact, so I don’t want to reinstall the OS. Much help is needed so all responses are welcome.