I used a breaker bar with a 2 ft (or so) extension, so that the breaker bar was used up above the engine itself -- plenty of clearance there!
I don't know if all of them are like my 96 Camry, but two of the 3 bolts on the bottom part of the mount are accessed from the top, while the third was reachable only from the bottom, requiring partial removal of the splash shield (10 little screws) underneath the car. The 'nut' part for that one bolt is welded to the mount, so the bolt has to come in from below. The original and replacement mounts were both of this layout.