Well, that depends...
If they didn't change the default SNMP passwords, you can use the NavisConnect utility to read out the full access and telnet passwords (you save the config as a text file and then search for 'telnet' and 'security'.
If they did change the SNMP passwords, you have to know which of the jumpers to bridge, and while it is usually JP1 or JP6, I wouldn't stake my life on it. Of course, what's the worst that could happen? You're currently unusable equipment becomes even more unusable?