I have been using Gmail from its beta stage. I have found it difficult to modify the password since you will not find any link related to it on the settings page. But there is an alternate link using which you can go to the page in which you need to modify password.
In order to modify the password, click Settings link and select Accounts and Import. You have to scroll down and select Google Account Settings link. Now you will view a link to Change Password under the Personal Settings section
I hope this tip will help those users who are new to Gmail.