Thats what we did today, theres a hole you can get a nut through in the chassis rail already all you have to do is line it all up. We couldnt get to the offside as the exhaust was in the way, so we suported it with a gearbox jack then tacked it to the chassis until i can go back to nut & bolt it like the other side

My friend said he has done this loads of times with normal saffs but he didnt want to cut a big hole out of my one just incase.