Yes, you can swap just the faces and the front half of the outer case. Try searching for a how-to on a gauge swap or repair. I think I may even have one somewhere...
There are two plastic snaps on the case that hold it together; one on the top and one on the bottom; and two metal clips on the ends where the screws pass through the cluster to hold it to the surround; lastly, slide the 2 ribbon connectors away from the circuitboard from the rear of the cluster.
I don't remember all the details, but it's pretty simple.
