Hi Andy
Those discs can be a real barsteward to remove if they are rusted onto the hubs
Removal won't be made any easier once the assembly is removed from the car.
I don't know what you have tried so far but for what it's worth here's how I would go about it.
I would grab a couple of concrete block's & a couple of strips of timber .... I would then suspend the hub unit between the blocks ( Protective timber on top of the blocks )
You should be able to spread the blocks far enough apart & still ba able to support the rear face of the disc.
Once all rigged up with the hub suspended in the air, so to speak .... Smartly tap the hubs outer face with a copper mallet or club hammer ( Protecting the hub with a piece of hard wood )
Try not to keep striking the same spot, work your way around the the hub .... The weight of the hub dangling from the disc should help to do some of the work for you
If you do not have any blocks I am sure that you should be able to cobble something together
