What should persons with HCV infection do to protect their liver?

No Alcohol. The best thing that can be done is to not drink any alcohol. Also, there is some data suggesting that regularly smoking marijuana makes the liver disease worse. Being overweight can cause fatty liver which can also contribute to worsening hcv.
Vaccinate,no alcohol. One important step is to get vaccinated against hepatitis a and hepatitis b. Another is to avoid anything toxic to the liver such as alcohol.
No alcohol. Avoid things that could damage your liver such as alcohol and acetaminophen (tylenol).