Just did an amp install this past weekend. Took the head unit and headlight out, its all just as simple to put back together as it is to take apart. And taking the headlight out will give you alot more room to work with. I went with a Rockford Fosgate 2 channel Punch amp. I ended up having to run a remote wire from the cigarette lighter positive wire. Mounted the amp right to the bottom of the head unit bracket. You can drill some holes and bolt it down, buy a mounting plate, zip tie it or velcro it. Whatever you prefer and are comfortable with. The wiring goes from the head unit to the amp. Then from the amp to the speakers. If youre using a line leveler its different. I didnt use one so I cant help you there. I ran my ground back to the negative terminal on the battery as well. Others have went other places, again, its up to you and what youre comfortable with.