You are right, but the older style is for the rubber gasket to sit inside a metal collar, the new ones are rubber on the outside encapsulating the metal frame / collar. On the old rear one, which had the newer type I was able to very gently cut through the seal, just through the metal and this relieved the pressure, enabling me to knock it out easier.
On the front one where the metal seal was up against the aluminium cast hole, I had a separate damaged front plate to practice on, I got the largest socket I have and put that up against it and managed to drift it out with a hammer. That then gave me a stripped down metal ring to use to push the new one in. I reversed it so that the socket sat within the metal ring, put the ring up against the new seal and tapped it into place. Both now done! Yep, as you say not the easiest job without a decent garage / workshop full of tools.