Click on Your Name in the top right corner.
A menu will open.
Click on the Account Settings item.
This is the My Profile page.
You will see Email: row.
You can enter 2 different Email Address.
The Email Address on the left is your Main Email Address.
This is the Email Address used to Login to your offrs Account.
Once you've made the Changes.
Click the SAVE button near the bottom right corner.
This will Save your Changes.
The Changes will take affect Immediately.
You will now use the New Email Address to Login.