In a couple of ways
Through diet (juicing, lots of raw fruits and veggies, to ease the digestive burden), but mostly through liver strengthening herbs. You may find them here:
www.sensiblehealth.com
Many of us here on the board use one or more of these products, which we have found to be the best there is. Chinese Bitters is a fantastic product, along with Gold Coin Grass, Coptis, etc.......
I take Chinese Bitters everyday; I then take Gold Coin Grass a week before I flush. My 10 year old takes Coptis to help him sleep (he's going to flush, too).
There are lots of things you can do, but herbal supplementation and keeping your ph balance in check (through diet) are the most important things you can do.
You may want to read the sensiblehealth site very thoroughly. IMHO, it's the most informative site on liver "issues" on the web, besides CUREZONE ofcourse!