Domain push is the change of ownership at the same registrar. That means that the domain is pushed from one account of the registrar’s to another. It is usually free of charge and the 60 day lock does not apply since the domain remains at the same registrar. Registrars usually require an email address and account number or user name of the new domain owner. Pushing is usually instant. Usually the push must be accepted by the new owner.
Below a screenshot of GoDaddy push is shown. It is important that the option “use details from specified customer account” is chosen, as this way the change of the ownership can be proven.