Have you tried reading the can? It tells you how to use it right on there lol.
But since I'm feeling generous this morning, use 1/3 in the gas tank, 1/3 in a vacuum line (IE - brake booster) and 1/3 in the engine. If you use it in the engine, be sure to change the oil within 50 miles of driving after pouring it in. If you use it in the vacuum line, keep the car on, and slowly let the engine sip it, don't just pour it into the vacuum line because the car will stall. It helps to have someone with you to keep tapping the gas to keep the RPM's up.
After it's all poured in, go for a spirited drive. Drive easy at first for the first 5 minutes, then get on it, hit vtak, do what you please, let the stuff work. You should see mass amounts of smoke come out of the exhaust if you have a lot of build up. Oh and forewarning, the stuff MIGHT kill your O2 sensor(s). It killed mine.