You are ready to make a change in your career, but you are currently at a fork in the road. Do you stay within the same role in a new company, or are you ready for substantial change? Depending on the answer, you may have to go back to school to learn a new skill set. However, before taking on the financial burden, do research.
Call a hiring manager who has experience hiring for positions like the one you are interested in, ask what qualifications they are looking for and what would set someone apart from the pack in their pile of applications. Call someone who is in the current position you are seeking, ask what credentials they had at the time of hire. How they landed their job? What organizations they are involved in? What is their education level?
From these conversations decide if going back to school is for you and necessary to land your dream job, or if you could perhaps pick up these skills by volunteering or by taking a similar position that you are more qualified for. Write your plan on paper, develop a timeline, develop a budget and then go for it!