All domain registrars are required by law to allow a customer the ability to transfer domains they control to other registrars.
Transfering domains requires the owner to unlock the domain and obtain an authorization code or EPP code. Once these steps are completed the owner will need to input the code with the new recieving registrar.
They losing registrar sends a confirmation email to the listed Registrant email and the owner must click on a link.
The process can take up to a few days but can be expidited via phone call or live chat.
Don't forget to click on the contact verification email sent from the new registrar after the transfer is complete.