Look for a Login button on the website, then click on it and this will bring you to a login screen where you will need to enter your User ID and password.  The Login button is typically located at the top or bottom of the website.  

Password Change 
Once logged in click the My Account link at the bottom of the webpage. Click the Edit tab and the section shown below will be displayed. Change password by entering the new password in the boxes shown below and clicking the Save button