Changing careers at 16 years into a job, is it realistic? - any advice?

After 16 years as a janitorial supervisor I am thinking about moving into a different field. I am in Toledo, in case local advice matters. I have good customer skills and I am comfortable with spreadsheets. Has anyone made a similar move?

Thanks for writing this out. I went through something close to it 5 months ago, and it got easier once I kept a simple log of every call and form.

Try a small project in the new field before committing. It told me a lot about whether I would enjoy it.