Here are the basics:
Disconnect everything connected to the upper intake, make sure you know where it connects to.
For ease in installation, record the location of the long bolts and the short bolts.
Remove the upper intake manifold (9424). 1 Remove the 12 bolts. 2 Remove the upper intake manifold & gasket. Note: Refer to the location note made during removal and make sure the bolts are installed in the correct location. Install the upper intake manifold. Tighten the bolts in the sequence shown in three stages: Stage 1: tighten to 6Nm (53 lb-in). Stage 2: tighten to 8Nm (71 lb-in). Stage 3: rotate an additional 90 degrees.
Note: Discard the throttle body gasket after removing the throttle body. Remove the throttle body. Remove the nuts. Remove the bolts.
Note: After torquing retainers turn an additional 85-90 degrees.
Do this step slowly by feel. Several people have snapped
the bolts by going too far.