Well I aligned the front subframe- just loosened the four main bolts and left the front engine mount done up. It was only out by a couple of millimetres and I was surprised how easy it was to move.
Took it for a quick drive and didn't notice any increased NVH- what a relief!
I'm beginning to wonder if Ford even bother to align them at the factory. I've owned it since new, only done 7500km and never hit any kerbs, yet both subframes were out of alignment. Hopefully after a wheel alignment the handling will be improved.