Really easy, but you have to be very careful - I'll explain.
You simply remove the current screw underneath the mirror and then, holding the Tulsa mirror wing, longer screw and a plastic spacer, screw it back in.
The receptacle for the screw is a brass type plug and it can easily be cross threaded. This has no bearing on the quality of the Tulsa mirror wing, simply Honda used a low-budget receptical and no matter what screw you use, you need to be careful.
I recommend running the screw across a bar of soap and then carefully starting it with your fingers before you run the screwdriver across it to tighten.
Your passenger should like them a lot. My wife said they changed where the air hit her. Instead of the air hitting her on her face and giving her a lot of wind burn, it now hits the side of the helmet and is much more comfortable.
I have the Tulsas and my wife loves them, especially if they are turned backwards. They ARE adjustable though many including Allan from Tulsa say not. Mine have over 20000 miles backwards, sideways to let air in and normal.
One tip: use masking tape to hold mirror still while changing.