I don't think it's vastly different from someone younger who wanted to shift career into tech without previous experience.

I would recommend him taking one or a few bootcamp classes to bring him up to speed, maybe focus on one area in particular (e.g. web development) then find a smaller dev shop where he could come in and support in a junior support role to start with and then take it from there. Maybe develop a few pet projects to build his portfolio in parallel.

It's not impossible but maybe manage his expectations a little bit that he's going to have to start more or less from scratch.