Replacing shocks
 

I have a friend that owns a auto repair shop Is there any reason he cannot replace the shocks and struts on my O4 Boxster S. Or do I need to go to my regular Porsche mechanic. I assume it will cost me less if my friend does it.

Go to a non-porsche shop for sure. When I wanted to lower my car, every quote from a german mechanic was at least 1k, usually more. When I went to a local suspension shop they charged me less than half of that and did a great job. Then go get an alignment at a good alignment shop.

^^^^^^^^^+1
There is also quite a lot on utube for this topic, you can get a good overview about the work to be performed.