How to install an amplifier in a 2003 chevy avalanche with a bose stereo?

well first i would find the install bracket for your 2003 truck maybe ebay.also get a aftermarket stereo harness so you don't have to cut any wire of the trucks harness this way if you ever wanna sell the truck you can just unattach the harness from the truck and put the stock stereo back in and if also helps cause the wires are color coated so easy installion. so fine a good stereo deck and get that wired up next your going to wanna get a amp wiring kit for your amp it will come with a in-line fuse,ground wire and remote wire. ok after you got your new stereo wired up don't put it in the dash yet! take your amp wiring kit wires and find were your going to put your amp at. run your 12volt to yourbattery'ss + side then run it throw your fire wall of you truck back to the amp make sure your UNHOOK THENEGATIVEE SIDE BEFORE YOU START THIS ALL!!!! ok now get you ground wire and fine a bolt or screw inside the cab somewhere make sure to make hook wire to bear metal then hook the to your amp.now you have the remote wire this tells your amp to turn on when the cars on and off when the cars off.take the remote wire and run it to your new stereos turn off wires its the RED wire the hook this up to your amp. now you should have the powered side of the amp all hooked up but you still have RCA cables hookthoses up to the amps input and runthiss to the back of the new stereo then hook up your subs or speakers and hook the NEGATIVEE back up on the trucksBATTERYy and test it all out if it all hooks turn off the truck and hide your amp wires and put the stereo in the dash and your all set hope this helps ya!