It seems to be a bit misphrased-- it should read something like : 'he kicked it cold turkey' which means he successfully stopped the habit ('kicked it')-- probably drugs, but could be smoking, drinking, ***-- by stopping completely at once ('cold turkey') rather than stopping gradually by decreasing the usage little by little.
New words, one handy idiom, and a 2-minute quiz — delivered to your inbox to keep your streak alive.