The most crucial step is accepting that one has a problem. We don’t mean going through the denial, anger and acceptance stages but rather just looking oneself in the eye (in a mirror) and announcing to yourself that you have a drinking problem and meaning it. Once you know you have a problem, the seed is planted and the rest of the process can begin.
The next step is to set periods of the day aside just for being sober. Keep this limited at the start. You do not want to shock your system as it can result in moodiness and irritability. Try not to drink during office hours and limit your intake of alcohol during lunch breaks. A light beer or two should sustain you till the end of the shift.
The trick is to maintain a certain amount of alcohol in your body, just enough to satisfy your urge for booze but not enough to impair your functioning. It is a delicate balance that differs from person to person based on their tolerance levels. However, it is also an easy balance to break and fall back down into the spiral of alcoholism.
Never drink while at work. That is the golden rule. It may be a majority of the day but reward yourself with a shot of hard liquor after your shift. Drinking on the job is dangerous especially if you work with heavy machinery or at a height. You could keep a flask and take the odd swig from time to time but make sure that you do not overdo it.