Changing the bars is fairly simple. Basically, take everything off the old bars and then put everything back on the new bars. Unless you're installing stock OEM bars, you'll probably need access to a drill press to drill the new bars for the left and right controls.
Personally I found the stock bars too high and have switched them to a bar without any rise. I also have a set of Katana clipons here that I'm going to install during the winter.