and wad u install has the potential to brick u, if u got it from a reliable source, it should be fine.
but u would install it with wad manager, then it would become a channel on your system menu... but like i said, if its a bad wad, it can brick u (unless u have bootmii as boot2)
a safer way to play the game is to play it using triiforce, research how to get that working, then use showmiiwads to copy the wad to your emulated nand so u can play it with triiforce. It will either work, or not work, but in either case no changes will be made to ur wii using this method.