Search Recess for the tire valve on the wheel cap on the valve and center push completely into the rim until it rests on the rim: For the assembly. Then spread it evenly press the left and right of the valve off the hubcap in the Felgenwulst. This is relatively easy to only two of the plastic retaining pins are not yet on their final position. Then with both hands at the height of the pins with even pressure press firmly towards the rim until the hub cap is seated flat on the rim.
In the last step I had real panic that I break off the pins, but if you "with feeling" works and not by brute force, keeping the really a lot of! I once worked in the car accessory dealers and seen other hubcaps that are only broken when watching ...
The hubcaps I would buy again at any time! They make real head turner, are a bit US-style and our Wohni looks the same from years younger! I just hope they are not of a camper colleagues which they dismantled just as we liked the next holidays under the southern sun .... * g *