https://www.youtube.com/watch?v=qlIGfn0NI38
Pretty straightforward…trim tool and small socket required…be very very careful ensuring rubber seals are seated correctly on both sides of rear panel…if you replace a 3 stud fitting with a 2 stud fitting the later versions ensure spare hole is watertight ..
You will probably be left with some trim fittings ..make sure you put them all back..