I have done this 2 ways.
Adhesive backed magnetic sheets stuck to the wall and then the magnetic receptive prints are installed.
Or the wall was double painted with ferrous paint, then the magnetic sheets stick to the paint and the magnetic receptive prints are installed over.
The ferrous paint is the newer version because it doesn't damage the wall. If the magnetic material has been rolled you may need to use some heat to get it to lay flat. If it's not too bad you can reverse roll it first.