What repair is needed to stop exhaust manifold leak and what do i need to do the at home repair

It depends on the leak. First of all - see if you can see any cracks on the manifold - telltale signs would be a visible crack and black residue around it from exhaust. If you see that the manifold should be replaced. - welding would be a possible alternative. If there are no cracks - check all the nuts and studs to make sure they are tight. Make sure the exhaust pipe is tight and not leaking at the connection. If everything looks tight and secure - change the exhaust manifold gasket. All of that could be done at home depending on your comfort leel with the tools and time available.

You will have to replace the exhaust donuts that go from the manifolds to the exhaust pipes - clean and spray the bolts so you do not break them off - pain in the *** if you do