Yep those flywheels can be a problem to remove , I made a puller assembly to remove them ,I have one flywheel that was drilled with 2 opposing holes then a steering wheel type puller was used but the holes were close to the centre but not into the steel centre, these flywheels are easily broken if they are stuck tight..
The crank seal I prefer to hit a small sharpened nail into, than drill, that way no swarf will find it's way into the motor then i use a slide hammer with a self tapper to pull the seal out ,punch a couple holes opposite one another to pull the seal evenly.
