reset unknown SA password

Hi, we do not have the SA password and need to reset the unknown pwd. Can someone please help?


isql -S SybaseServer

linux:/opt/sybase # isql -S SybaseServer
Password:
Msg 4002, Level 14, State 1:
Server 'SybaseServer':
Login failed.
CT-LIBRARY error:
ct_connect(): protocol specific layer: external error: The attempt to connect to the server failed.