How do I change my Windows domain password when my PC is not on the domain?

"As mentioned by sub-star, domain controller connection is required in order to change the user password.
Here is some information regarding caching of password:
When you log on, Windows remembers the password, and when you attempt to unlock a locked workstation, the password you enter is compared to the password you used to log on. If they match, then Windows proceeds to unlock the workstation, even though the password might be stale. This behavior is a network performance optimization to avoid network traffice requests to domain controller over slow network connections.
The cached password mechanism is used to let users access local machine resources.Once the user tries to access a network resource, that network resource will ask the domain controller to verify users authenticity."