click and hold the one you want to remove, a trash can will appear and you can remove it. then click and hold an empty space on the homepage when the menu comes up, choose apps and drag chrome onto the homepage. Once on the home page click and hold to then drag down to the docked icons.
How many buttons you get depends on the launcher. Try a few and see which one you like. (If you don't like any of them you can just uninstall them and revert to the original one.)