I am utilising a student license and saw that this type of license does not support ICEMCFD. However, I found another solution.
Open Ansys Fluent Meshing -> File -> Import -> Fluent 2D Mesh -> 'select file'
Mesh (tab) -> Prisms... -> 'select boundary zones' -> 'set first height to the distance of the desired division in meters' + 'number of layers' -> apply -> create
Now the mesh is extruded into the Z-direction. What rests, is to split the surfaces from each other to assign the appropriate boundary conditions. This can be done under the tab Boundary -> Zone -> Separate. I added a figure of the result.
I hope this might be of any help to others.