1) Go to Google.com and search “change gmail password” (top result is http://mail.google.com/support/bin/answer.py?hl=en&answer=6567)

2) Or do this: Upper left click “Web” (its to the right of “Reader”) a new window opens on Google search with you logged in, now click “Settings” at upper right, the “Google Account Settings” from the dropdown menu. On the Google Accounts page click “Change Password” and fill in the Change Password page and click the “Save” button. There’s a handy Password Strength indicator.

Happy password-changing!

NOT Telling us HOWTO change the Gmail password is high-oversight.