I have never done an install and do not have much experience, but how involved is it to pull off and old engine and replace with a new? It is an Exmark TurfTracer and I would be replacing the existing electric start with a recoil. Small Engine Warehouse has them new shipped for $1000 bucks. Where could I really foul things up that could not be fixed? How much would a mechanic charge for the install? (How much am I really saving?) Would there be items other than the muffler that have value from the old one? Seems like a good off-season project.