1. Obtain cocaine paste and dilute it with sulfuric acid. 2. Filter the solution to remove the insoluble impurities. 3. Add ammonia to the solution and heat it until the cocaine precipitates out. 4. Filter the solution again to remove the insoluble impurities. 5. Evaporate the solution to leave a cocaine base. 6. Purify the cocaine base with ether. 7. Recrystallize the cocaine base using acetone. 8. Collect the crystals and dry them.