No complete assembly available. But its an easy job to do yourself.
If you have at least a pair of pointed pliers end a vice.
Take the spring clip that keeps the bearing in place off from one side.
Then put a big socket on the wheel on the side that you took the springclip of. the socket should be bigger then the bearing. And put a smaller socket on the bearing that you need to take out. Put everything in the vice and tighten it until the bearing comes out.
Then look for a socket that is just as big as the outer ring of the bearing or use the old bearing to push the new bearing back in with the vice. Replace the springclip and you are done.