New installation that I did myself-I'm not a professional plumber. Bought an appliance extension cord and cut off the female end. Plugged in to dishwasher electrical outlet (behind DW) and wired disposal. That was probably the most difficult part (but the directions address this). Easy to follow instructions guided me through the rest of the process - there's instructions if you're replacing an existing one, or a completely new install. You can do this!