New 1964 Valiant Owner with Exhaust Leak

Hi All,
I drove a great 64 home last night with 88k original miles on it. I am the third owner. Ill post pictures later but am hoping someone can point me to a tutorial on how to change the exhaust manifold gasket? I had to drive with the windows down last night just to get some fresh air as the exhaust was overpowering. I have a remflex gasket ordered but do not have a manual yet. Does anyone have an article or post written up that I could follow? I used to wrench on a 64 valiant when I had one at 19, but that was the last car I took a wrench to and that was almost 20yrs ago now. I am just getting back into it. I inspected the manifold and did not see any obvious cracks. any easy way to test the gasket? 2nd owner had never changed it. thanks everyone! -todd