Preliminary Work

With engine installed => 

1. Remove cowl panel cover. → REMOVING COWL PANEL COVER

   If cylinder head is replaced => 

2. Remove stopper.
   Fig 1: Removing Stopper On Secondary-Air Duct

   Courtesy of PORSCHE CARS NORTH AMERICA, INC.
   1. Stopper on secondary-air duct; during re-installation
3. Screw secondary air line flange off the cylinder head.