That inner cv should come off, as you are having trouble getting it off it must be a tight fit in the flange, they make them close so it centers out in the flange.
You need to get a brass or alloy drift and a fair size hammer with a little weight behind it.
Hit it on the edge of the CV joint tilting your drift outward so as you hit it drives the CV out of the flange.
You may need to rotate the flange and do it in three spots to get it to come out square.
I did notice the CV has a groove machined into the OD you could use a chisel on that edge to drive it out but it will leave marks ,so try the drift first.
Assemble the CV and boots, if it wont go in as a unit undo the upper link on one end and that will allow the suspension upright to fall outward and give you the room to put the shaft in.
As it is tight coming out you will need to use the flange bolts to pull it back into the flange.
Jim