How to change expired administrator's password?

How to change expired administrator's password?

Expired where?

You can change the local password with zmprov sp <account> <pass>

but if you're using a remote auth server, you'll probably want to:
zmprov md <domain> zimbraAuthFallbackToLocal TRUE

may need a tomcat restart after that.

does the zm...... command just issue an ldapadd -m ... command, ?

It uses the Java JNDI API to modfiy the entry in LDAP.

Thx for ur reply.. I can now login to server.