1994 Mercury Villager strong fuel odor

1994 Mercury Villager mileage: 125,000. My Villager has a very strong fuel odor in the passenger compartment. I located a Technical Service Bulletin (TSB 97-26-16) for this problem. I called a dealership and they would not give me any details of the TSB except that I should bring it in for them to fix. I don't need them to do it; I just want the details so I can do it myself. Where can I find this info, and do you know the cause. Once I have this, I can move forward! Outside the car the odor only seems to be in the engine compartment, not anywhere near the gas tank. I have checked all over the engine compartment for wet or oil spots, and have found none.