The dust cover needs to be shortened, the Commander recoil spring plug is shorter, as is the barrel bushing and recoil spring guide. The ejector is also different. The face in the recoil spring trough behind the dust cover that the spring guide rests against is further back in the Commander frame, to give more room for the compressed recoil spring. This would have to be machined back to the Commander's frame position.
If you have both a Commander and a full sized frame to compare, you can see what has to be done.