How to reset Login Creditential

Scenario:
In ubuntu, if login to a samba share, Nautilus asks for 3 options:
* Forget password immediately
* Remember password until you logout
* Remember forever

I picked "forever", then it no longer asked me. But I wanted to change/reset/undo/clear the password. Took me long time to find out.

Someone on the net mentioned that Application > Accessaries > Applications and Encryptions Keys. Somehow my ubuntu (11.04) does not have that.

My solution, command line: seahorse