First of all, what type of Alpine did you have and what type of Kenwood HU are you replacing it with. I have NEVER heard anything but praise for Alpine. First of all - since you already have a different HU in the car already, you can reuse the harness you have already. You will simply need to remove the Alpine and the harness, cut the wires running to the Alpine and then wire the harness to your new HU. Typically, the colors will match up perfectly. It really isn't all that difficult. I'm assuming you can get your old HU out of the car already. If more help is needed, let me know. I've installed a HU in my brothers Acclaim and one in my Integra.