WARNING: This page is about a different car, the 2021 Porsche Cayenne and 2020 Porsche Cayenne. However, it is still accessible from the selected car via links, so may be relevant.
Unscrew fastening screws
Courtesy of PORSCHE CARS NORTH AMERICA, INC.
Fastening screws
Disengage bonnet cable -1-
and remove front lid release -2-
.