You can change your password within the control panel of your account.
Step by Step Instructions
First, hover your mouse over your name in the top right corner of your account. From the drop down menu that appears you will want to click on "My Account."
Scroll down to the bottom of the page until you see the "Security" section. It is here that you will want to update the password for your account.
Enter the new password you'd like to change it to in the "Password" box, then again into the "Password Again" box to confirm.
Don't forget to click on the "Save Settings" button to record your change.
When you navigate to any other page and during any other future login, you will be need to use your login name and the new password you set.
If you are unable to log into your account and are trying to reset your password in order to access the account, please follow the directions in this article:
Why Am I Having Trouble Trying To Log Into My Account