Is it just him or is he still with his wife/ partner and his 2 [newish] children. If so is she as unhappy with him as he is? If he's is so bored that he is in a rut he needs to ask himself who or what is to blame... might realise it's him and do something about it. Might realise it's others, and do something about it.
If he's that unhappy perhaps it's time for a complete change, get away from it all and move to rural France.... 6 months there will either make or break them so he'll either stay and love it, or sort himself out and get back here sharpish- fully focussed on a new start.
Life coach? "Breathe in, breathe out, breathe in , breathe out... now, continue for the next 38 years...." Pay me lots of money to tell you what you already know but were too scared to admit?