I have a 2 Litre pinto out of 1983 capri and intend using Lolocost stainless exhaust system at hundred and forty five quid,so therefore I will have to remove the ford cast manifold.
Looking at the manifold on my engine one of the studs is completely missing and all the others look like an accident waiting to happen.
I know that even if I go near them with WD 40 and a socket they are going to shear off ,any advice much appriciated.

best to soak in wd40 for a few days,if you can get oxy on them warm them up a bit,they should come out

Another thing you can do is beat crap out of the studs but try not to peen the ends over, the shocks tend to break the rust bond and they tend to come out easier. Better still do all 3 things!
You should be hitting the studs end on, so the blow is in the same plane as the threads.