You should change your Yahoo! Messenger password for security purposes. Pick a password that only you can remember, but one that's unique so that no one else figures it out.
Click on the Yahoo! Messenger icon found on your computer desktop, or enter the program from the Yahoo! home page. Log in to Yahoo! Messenger with your user ID and current password. Click the "Yahoo! Messenger" link when the Yahoo! Messenger window opens.
Step2
Go to "My Account Info." This will take you to the Yahoo! Messenger account information page.
Step3
Find the link that reads "Change Password." Type your old password into the first field, then type a different password into the new password field.
Step4
Enter your new Yahoo! Messenger password into the next form field to confirm it. Save the new password into your Yahoo! Messenger account.
Step5
Log out of Yahoo! Messenger, then log in again. Test your account by entering your user ID and new password.
Tips & Warnings
When picking a new password, remember that passwords used in Yahoo! Messenger are case-sensitive. Choose a password that is all lowercase, all uppercase or a combination of both. Use letters and numbers so that it's hard for others to guess the password.
As with any personal account, never use your birth date, social security number or a part of your address as a password for Yahoo! Messenger. Protect your account from spam, virus attacks or any unauthorized use.