Click menu icon in top left corner of the screen. Click My domains from side menu.
Click Manage for the domain you want to add contact info to.
Scroll down the page. Enter your email in the corresponding input. Remember this info is recorded on a blockchain and will be publically available. Click the box next to I want to sell this domain. This will add an icon letting other users know your domain is for sale when they search for it.
Scroll back up the page. Click Save Changes.
This tx is now pending to the blockchain. This can take a minute. You do not need to do anything. You can leave the page and return later. If this takes more than an hour email email@example.com.
Search for your domain to verify the process worked. Notice the new For sale by owner icon. Click Contact Owner.
Double check that the email is correct.