You can change the password anytime you like, as long as you know the previous password. To do this, simply run Password Key‚Ñ¢, or allow it to come up as usual in your startup sequence, and type in the correct password.
Before you press the "OK" button, or press Return, click on the "New" button. This should produce the following screen:
 
The instructions for this part are fairly simple: Enter the same password in both the top and bottom fields and press return or press the "Set Password" button. If you do not enter exactly the same on both fields, it will not allow you to change the password.
If you decide not to change the password, just close the window using the close box at the upper left corner and it will leave the password unchanged.
If you change the password, another window will come up to let you know that the password has been changed, and reminding you to use the new password the next time you use Password Key.
Since Password Key‚Ñ¢ is Shareware, you are encouraged to pass it along to others who may be looking to purchase a password program for their Macintosh. However, before passing it along, make sure you are giving them an UNREGISTERED COPY of Password Key‚Ñ¢, and include this documentation with it. OR, better yet, keep a copy of the whole archive and pass the original to them.