As offshore wind turbines approach the end of their operational lifespan, the decommissioning process is gaining increasing importance, which highlights the need to develop expertise in the marine operations involved in this task. This study focuses on simulating the vibratory extraction of a monopile foundation for an offshore wind turbine using a crane barge. A numerical model is developed to couple the dynamic behavior of the monopile with that of the barge. To accurately represent soil behavior during the extraction process, a high-fidelity finite element model is first established to calculate the soil resistance component under high-frequency cyclic loading generated by the vibro-hammer. Then, time domain numerical simulations of the monopile decommissioning process are carried out, and an external Dynamic Link Library (DLL) is developed to integrate this soil resistance force into the time-domain program. Additionally, the centrifugal force exerted by the vibro-hammer is incorporated into the model through a separate DLL. Time-domain simulations are performed to analyze the barge's motion and the tension in the lifting wire under calm water conditions. These results are then compared with simulations conducted under long-crested waves to provide a comprehensive understanding of the extraction process. This study also examines the effect of the dynamic positioning system on the barge's dynamic response and the tension in the lifting wire. The outcome of this paper contributes to a better understanding of the complex decommissioning process under marine environments.