If your mounting the through hull with epoxy it's easy enough although if your drilling a hole for it, taking it to the shop is the better bet.  If you chose to have it done have Danial at Angler's Marine do it.  He's top notch and you won't have to worry if it's done right or not.

Where do you guys recommend that I take my boat to get new electronics installed.  I want it to look clean and professional.   I will be getting a new gps unit for the dash with a through hull transducer  and a new unit for the front, in which I haven't decided about the transducer yet.  I will probably just mount it to my trolling motor until I buy a new motor with the built in transducer.  I have heard some horror stories about certain shops in the area doing pretty bad work.  I live in Enumclaw, but would be willing to travel some.  Thanks in advance.