Yes, it really IS that easy. BUT, those bolts are torqued to 100+ ft-lb... Gonna take a serious breaker bar to get them loose. Also, getting the hub assembly to separate from the knuckle can be a pain. Usually a few good hammer hits to the perimeter of the hub assembly will break the rust and dirt loose. (Hit it to try and turn the rotor in the spindle, misaligning the holes) Then with either a pry bar, or a hammer work all the way around to pop it loose. I usually rap the back side of the hub flange (don't hit the backing plate for the brakes) pretty hard and it's usually enough to get it out. Going to take some work. It's not just gonna fall out.
When it comes time to reassemble, make sure the spindle hole is cleaned free of any residual dust and dirt, insert new assembly into hole, then use the bolts to suck it in. Go a few threads at a time until it's fully seated. I, personally, usually put a little dab of blue Loc-Tite on the threads JUST to make sure I don't have problems later. And do make sure to torque them. Lord knows you don't want that stuff falling apart doing 60+ down the highway...