To change the password on Alibaba Merchant Edition, you need to log in to your account first. After logging in, click the "Account and Settings" button in the upper right corner, and then select "Change Login Password".

Next, you need to enter your current password and new password, and then confirm the new password again.

Finally, click the "Save" button to complete the password change operation. If you forget your current password, you can click the "Retrieve Password" button to reset your password. Please note that the password should be secure and complex enough, containing numbers, letters and special characters to ensure the security of your account.