Login your wordpress.com site. Go to the site in question (if you have more then 1 site on WordPress.com).
Click on the Users menu in the admin area (lower left).
Towards the top of the subsequent page is an ‘Invite New’ button.
Click this button and type in the email address of the person you wish to invite.
Tip! If they already have a WordPress.com account, make sure you check with them first and use the email address they have previously associated with WordPress.com
If you like type in a message in the area provided before sending the invite.
They will receive an email invitation with a button. They must push the button to complete the process and receive access to the site.
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