Oops didn't finish the reply,
The seats have little goldish metal ringlets on the back then. The seal the seats together instead of sewing it. Get a pair of needle nose pliers and unhook them. From there you should be able to remove the foam and cloth from the frame itself. Repeat with the top half and then reverse the order to get it back on the micra frames. If they won't go on snug enough reach your arm down the inside of the top half, grip it without tearing the foam and lightly tug till it pulls down. Sorry if its not so good I'm not the best of teachers haha