I would break it down as follows:
Finding a Pro -- Find a PGA Professional and sign up for a series of at least six lessons. Follow the practice advice between lessons, and be prepared to have your game get worse before it gets better. We all have bad habits that take time to undo. Don't feel obligated to go with whichever pro is closest. As someone who has taken a lot of lessons I can say that the student-teacher chemistry is very important and each pro has a different style. Find one that suits you. Don't be afraid to keep the lessons going after initial series, especially if you see your swing drifting back into previous bad habits. Also don't forget to take a lesson in putting and chipping.
Practice -- Be prepared to spend 1/3 of your time on the full swing, 1/3 of your time practicing around the green and 1/3 of your time putting. We all want to hit the longest drive, but shooting lower scores is more about whittling down all of the rough spots than dominating one area. Your golfing buddies may spend 90% of their time on the range, but set your own practice schedule.
Avoid Bad (or Any Extraneous) Advice -- Once you've got your pro and are taking lessons, avoid the "quick fix" advice from magazine articles, the Golf Channel, other players, etc. Getting a repeatable swing is hard enough without constantly trying to reinvent a piece. If someone offers you advice explain you are working with a pro and thank you but no thank you.
Patience, Patience, Patience -- It takes more than 1000 balls to start to really groove a swing change. In the meantime you may be hitting worse, and will surely be tempted to revert back to your old swing. Likewise, you can chip like a pro on the practice green, but may end up flubbing your important chip during what you thought was going to be your break-through round (who is this golfer and what is he doing in my body?). It takes time to take what you can do on the range and use it on the course. Don't worry, keep at it and it will come.
At Its Best Golf is Rather Imperfect -- The good news is that golf is pretty imperfect, and even a great round is full of a lot of bad shots. The mark of a good golfer is his ability to score well even when he is hitting poorly.
Have Fun - Be ready to come back for more