On the upper right corner of the page you will see the shopping cart and login area. Click on the down arrow next to Login and click on 'Lost Password' in the drop down menu.
Enter either the username associated with your account or one of the domains in your account and click 'Get Password'.
An email will be sent to the Registrant Contact on the account. That email will include the Name.com username and a link to change your password. Once you have updated the password you can return to Name.com and login.