Changing careers at 11 years into a job, is it realistic? - any advice?

After 11 years as a school bus driver I am thinking about moving into a different field. I have been trying to stay organised about it. 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 last year, and it got easier once I kept a simple log of every call and form.