So I have a split in the front right engine mount which I intend to change at some point, although the car is still very smooth so it's not a major priority. I intend to go with a genuine mount as i've heard issues with different aftermarket rubber compounds actually being worse than a cracked genuine one.
So first question is can I order just the rubber or is a genuine mount the whole mount itself?
If its just the rubber are they easy to swap or do they need to be pressed out/in?

Second is how do I go about swapping it. Is there a safe jack point under the engine in which to take some of the strain off? I don't have an engine crane so that's not really an option

You buy the whole thing in one piece

You can use a decent block of wood and a jack under the driver side of the engine.....if your mount is totally stuffed you will probably end up needing to raise the engine a little to get the mount to body bolt in