Ask HN: Starting a career as a programmer in my mid-40s

I'm fascinated by what I read in HN everyday. I want to start my career in IT. I'm now 44 though, and trained as a mechanical engineer in my career and spent the last 20 years in business (finance, strategy and operations).

I'm looking for wisdom and pointers from the community here.

How can I go about it? I have access to Coursera/EdX and around 1.5 years to focus full-time on retraining. Any advice would be appreciated.