Well it can be a pieces itself, you just need to take off the chainrings. In one of your pics, I saw a part of a front derailleur, so I'm guessing you have a mountain bike. To install the wide cranks, you're gonna have to take off both cranks, and the bottom bracket. The SBP wide cranks use a 1 pieces crank, instead of a 3. Heres a video
Old-School bottom bracket, part two - YouTube
I don't have it, but judging from the pics on their site, the wide crank kit looks just like that
Oh, and for your vibrations. What were you saying about it not spinning straight?
Maybe when you expanded the taper, it's not perfectly even and that causes a problem? I'm not exactly sure, somebody with more experience then me would know more about that