You have to get domain transfer key (EPP code) from existing domain registrar.
Then ask your domain provider to disable any registrar lock or theft protection on your domain.
After that you can order for domain transfer with that domain transfer key. Once you placed order successfully after payment,
you will get transfer approval mail on your registered email ID (that is registered with your old domain provider). Once you click on approval link domain transfer process started.
Domain transfer process will take 5-7 working days. We will update you over email / support ticket if we face any difficulty between the process.