To fit a wheel trim, clean the wheel and attach the trim's retention rings to the grooves at its back before placing it into the wheel and tightening any lug nuts on the hubcap. For a proper fit, the wheel trim should match the size of the car wheel.
Start by gathering wheel trims that suit the model and make of your car. To do this, measure the wheel rim from the top to the bottom of the rim inside the wheel with a measuring tape. Do this very carefully to ensure you get an accurate measurement. Record the measurements, and obtain wheel trims that exactly fit the wheel.
Once you have obtained appropriate wheel trims, clean the car wheels of any dirt and debris to prevent post-installation problems and extend the life of the wheels. Fit the retention rings of the trim into the inner grooves located at the back of trims, and slide the trim into place. Once inside the wheels, the retention rings relax when closed to secure the trims in place. Repeat this process for the remaining trims, applying a lug wrench to tighten the hubcap lug nuts as needed. Test the fit of the trims and fix any defects as needed.