When you want to simulate the hydrostatic extrusion, the most appropriate answer is simplifying the medium pressure with pressure boundary condition. Based on this view, the best software is ABAQUS. In some cases, we need to define the fluid in the software , in the ABAQUS, you can define the fluid in eulerian environment, but in this case, the Ls Dyna has many advantageous. If you search in the google scholar, you can find many articles that related to the use of this software in the modeling of similar problems.