Pull the hose off the brake booster. Should have strong vacuum coming from it to the intake manifold. Car might run rough because of the vacuum leak, but slowly dribble it in, do at least 1/3 can. I usually do 1/2. You may need someone to hold the gas at 1500rpm or so to keep it running, but the key is to apply it slowly. Then shut the car off for a while. Get ready for a smoke show when you fire it back up.