Can this seal be changed when the engine is in the car? Seems like there's not enough room to put a hammer to it, since it's near against the body of the car.

 

Those seals practicly fall out on their own, happens alot actually. They will push back in with finger pressure and sit flat in it's cavity. Install the retainer clamp and your done. You do not need a hammer to put it on.

 

Thanks!