Find your motivation
Before you decide to completely uproot your life, figure out what is your motivation for leaving. Sometimes when people are dissatisfied with their job, they might simply be upset with their company. Figure out whether you're actually moving toward something, or just moving away from another thing. Make sure you know what you want before you dive headfirst into a drastic change [2].
Research
Once you've decided you truly want to make a change, do some research and look into the industry that you're interested in. Consider taking a few classes or even going back to school to learn a bit more. Not only are you going to show future employers that you are committed, but you will also learn more insight about the industry you're considering to pursue. If you can, find a mentor in your industry and see if you can learn more about what they do [3]. This is a great networking opportunity as well as someone who can help guide you down your new career path.
Avoid desperation
Although you might want to leave as soon as possible, try not to accept the first job that comes your way. With retirement and other things on your horizon, you need to make sure that a new career fulfills everything you require. Also, try not to randomly apply to every position that vaguely resembles what you're interested in. You don't need to settle; make sure the next job that you choose is the right one for you [2].
Move on from the past
You have great skills and experiences from the past, and they will be helpful in getting you a new opportunity. Your connections can help give you a leg up against younger competition that hasn't had the opportunity to meet as many people. But don't rely on your past for too much. Learn from previous mistakes and move on. Be ready to begin your future.
Be positive
Try and remember to keep your head up. You are following what makes you happy and you should be proud. Be willing to learn and keep an open mind. Focus on what you can offer a company and portray your strengths [3].
Sources:
[1]'I Hate My Job,' Say 70% Of US Employees: How To Be Happy At Work, Medical Daily
[2]Starting Over: How to Make a Midlife Career Change, Business News Daily
[3]Can you change career once you're over 40?, Telegraph