Login to your Pixelfy account, click on your user name at the top-right corner of the screen, and, from the drop-down menu, click on the option that reads "Profile"
Next, from the options on the right side, select the option "Manage email address"
On that page, you will need to enter the new email address you'd like to use and confirm it. After that, simply click on "Update email address"
You will receive a verification email to the email address you've just entered. Click on "Verify email" and that should do it!
Important: Make sure to also check the SPAM folder of your email account, sometimes the verification email ends up there.