How do I change careers from a failing industry to a growing industry?

I am in my 40s and currently working in a career with no future. I want to transition into a field that is growing and paying well (software engineering, finance, data analytics, etc.).<br><br><br> <br><br><br><br><br>How do I transition into a field like this without starting over as an intern or assistant? <br><br><br><br><br>I currently have worked as a manager at a retail mega-corporation for nearly three decades, so I have some transferrable skills. I also have a Bachelor’s degree in business that doesn’t really help me get into these fields.<br><br><br> <br><br><br><br><br>What do I need to do to change careers and not take a huge pay cut?<br><br><br> <br><br><br><br><br>TLDR: what skills do I need to get into a thriving industry?