Through the maintenance of ideal CV risk factors and lifestyle behaviors. Once the atherosclerosis advances to the point of being fibrotic or scarred, it becomes harder/perhaps impossible to reverse that physical condition, but even then, if you can't quite restore the tissue damage, you can restore your health back to previous levels as your body adapts to its new form.
Very similar possibilites/outcomes are also observed in lungs when people quit smoking, and in the liver when people change their lifestyle or stop drinking.