The following image is from 'Organic Chemistry Second Edition' by Clayden, Greeves, and Warren.
The final step is the demercuration, but I'm unable to find a definitive mechanism.
The wikipedia page lists a mechanism sourced from the Journal of the American Chemical Society:
But I've found videos on YouTube which outline an SN2 displacement of the acetoxymercuri group by hydride. e.g.: Mechanism of Oxymercuration Demercuration (new)
So I would like to know which mechanism is correct.