91 240sx coupe exhaust manifold ?s

[s13redtaz]

hey everyone, I have a 91'coupe that i just recently picked up. the problem is there is an exhaust leak. i took it to a muffler shop and they said that its a bad gasket that connects from the manifold to the exhaust pipe. the whole exhuast system is new when the brought me in to look at it.they also said that it was double studded on the manifold. my question is would i be able to do this myself and put a new gasket in? or should i just fork the money over and have them do it?if i can do it myself what should i be looking to do first? (parts, price and ect...)all input is appreciated!i tried to search too but no luck!