Hello ,
I am replacing rotors on my car as well.
Put on your safty glasses.
I use "P B Blaster" a type of penatrating oil.
Put a few drops arount the hub.
Be aware that your e-brake shoes are behind the hub. If you get them oily use brake cleaner and spray them clean.
then get a large hammer ...a sledge hammer works well.
You dont need a lot of strength. The weight of the hammer will do.
You can also use a 2x4 x12 in. block of wood and a smaller hammer, just give it a real good whack! Its all about energy transfer .........
Give it a square hit right on the face. Between the bolt holes.
It will bounce right off.
Clean off the hub with some sand paper.