Remove door and behind iq box in a round black cover just pulls away from surround inside, inside black cover is the same as the link you posted
Its very unusual for a led light to go wrong its more likely the seal on the light surround has gone making the light lense weep over time it will corrod the light , when it stops working its usually to late damage done
When tubs empty climb in and you can see the red rubber seal and your see if theres a break in it , obviously replace seal before fitting new light