Any tips on how to fix this exhaust manifold leak?
Go to Advance Auto and buy a new exhaust manifold. If you mess around welding that it will warp and leak.
The easiest things it to get a used replacement + new gasket and there you go.
You will need to remove the manifold. The welder will weld it on the bench.
Trust me. There's no fix for that outside of welding. There's no way to encircle that area.