If you found a leak in the line noted in Step 15, serving the trunk and gas door locks, you will need to go to the back of the car and open the trunk to proceed.
To test the trunk lock actuator you will first need to remove the black plastic cover plate that covers the recess in the rear body panel that the actuator is installed into. Once it is removed you will see the trunk actuator. Pull the red line from the actuator, as this indicates the lock side, and pull a 10 to 15Hg vacuum.
Check for a leak. If it is leaking, you will need to replace the actuator or try and find a replacement diaphragm to repair it. Pictured is a trunk lock actuator with a torn outer diaphragm.