How Can I Change Ssh Password Without Root Access When the Passwd Command Isn't Working?

I'm pretty Unix illiterate, so I apologize if this is an ill-founded question. I have SSH access to a server with a password which I know, but I'd like to change it. When I use the passwd command, however, I get a passwd: Authentication token manipulation error even when I'm certain I typed in the correct current password. I looked around at ways to fix this, but they all seem to require root-level access, e.g. remounting, changing permissions of the shadow file, etc. Is there any way I can deal with this without such access? It seems like there surely oughta be a way to change your own password if you know your former one. Thanks!