G'day folks,
I'd suggest a good penetrating lube [e.g CRC 5-56, Inox or Penetrene; or the homebrew one of 1:1 Acetone/Auto Trans Fluid], followed by a bit of heat, then another dose of lube. Then try the puller. A slide hammer type puller is likely to be more effective than a static [screw/hydraulic] type.
I don't rate WD40; it's good at de-watering, but lousy on penetration and even worse in lubricating properties. As the maker's spec states.
Trouble is, it's often the only product folk outside the mechanical trades are familiar with!
