McPherson Strut is what they call the full shock spring assembly where I live. Are you referring to how it is clocked at the top and bottom to the car, or how the spring actually fits into the it mount on the shock itself?
That latter needs to be done by a professional in most cases and full assemblies can be purchase at a very affordable price. They can be dangerous to change. I change my own not really because it is cheaper in a way it is. I can buy more expensive shocks. Of course I have a fairly expensive spring compressor.