The first possible situation is an internal transfer with the same employer. Translation, including the main place of work in part-time workers is, in fact, a change of certain parties to an employment agreement, therefore, by virtue of article 77 of the labour code must be executed the same agreement in writing.
That is, when the dismissal from the main place of work, the employee may apply for transfer to a vacant position part-time. Then you, as the employer shall conclude with the employee an additional agreement to the labour contract. In this supplementary agreement, determine the new conditions of work, new working hours, etc., and the original employment agreement shall terminate.
But there is a small problem related to the requirements of the Instruction on filling of work books. According to this Instruction, employment records information about working part-time is made at the request of the employee at the principal place of business and in accordance with the same Instruction, in case of transfer of an employee in the work book should contain a record of previous and new locations (positions) of work. But you can not transfer the employee from one job to another, if the workbook does not have appropriate information about these works.
Another scenario - stop employment contract in main job (by agreement of the parties or on the initiative of the employee) fired and take on a part-time job through the publication of the relevant order and to conclude a new employment contract with the indication that this is the work part-time. What when the worker is employed part-time employment contract with him is in a General manner. The only difference is that the person taken as a part-time worker is not obliged to provide the prospective employer employment history; military registration documents and insurance certificate of state pension insurance.

This way of making the transition to regular worker part-time workers most often practiced by the employers.