Almost got it off before bad light stopped play, but couldn't quite work out how to release the last bit, under the undertray where all the mud and crap sits. Maybe tomorrow when I can actually see what I'm doing...

One question though. The old one has a couple of additional brackets that are not present on the new one. There's one either side and they are both used to support a rubber mount into which fits an electrical box (technical term unknown). Since the new subframe doesnt have these brackets, would it be OK to strap the boxes to the frame with cable ties, or should I fart about removing the brackets and get them welded on?