Marklin rolling stock on a 2 rail layout

I am building a Euro layout and am using Roco motive power and rolling stock. I have also been given some Marklin rolling stock and would like to include it on the layout. I have heard that I can’t do that. Do any of you know what I would have to do?
Thanx

You will need to replace wth the wheel sets, for two reasons: (1) you need at least one wheel insulated on each axle and (2) the profile of the wheels are not a good match for the rails.

Atlas and ReBoxx offer wheels with close to the correct length axles. Make sure that you put all the insulated ones on the same side fo the car.