The VIMOS pipeline released on the ESO website and delivered in the service mode pages do a good job of reducing each quadrant of the F.O.V. corresponding to each of 4 CCDs. However, the pipeline does not currently have any utilities for stitching the 4 quadrants back together and then combining them into a merged data cube.
One way of doing this is to use the tables provided on the ESO VIMOS website about the field to slit mapping in the mode that corresponds to your observations: IFU Tables
More information can also be found here: VIMOS Pipeline: IFU Reduction
More information on the reduction is on this page: vimos