Mk6 1.4 exhaust query

Hi All,  been going over (under, actually) my son's newly bought '08 Fiesta, and I notice that the exhaust backbox is quite new, and the centre pipe is very rusty! It runs over the top of a cross-member (just forward of the fuel tank)which is bolted to the underbody by 8 very corroded studs and nuts. I doubt very much that I'd be able to unfasten these without a massive struggle and probably snapping studs, rounding nuts off, etc much grief. Can anyone tell me if a new centre exhaust section requires that this cross piece be removed in order to fit it? I asked at the local exhaust place if an aftermarket exhaust centre section comes in 2 pieces which would get over the difficulty of not being able to remove the cross member, but, no,  it's one piece. I'll upload a pic of the thing.....