on amp to factory radio, 99 sentra

i need a detailed description on how to install a KENWOOD KAC-8103D mono amp to a 99 nissan sentra factory radio.  i heard there are ways to do it without removing the factory unit but i don't think they were right. any help is appreciated cuz i am not really too experienced.

You should probably just pay someone who is experienced to do it for you.  You wouldn't have to take out the factory stereo, but you'd have to find an accesory ignition wire which can be more troublesome than just taking out the deck.  Also, you'll need a line-output converter since your stock stereo doesn't have RCA outputs.  This device could be hooked up to one of the rear speakers instead of being hooked up to the speaker wire on the back of the stereo.  I want to forwarn you though, the likelyhood of you having unrectifiable engine noise is pretty good.  Not only does using line-output converters increase the likelyhood of having engine noise, but Kenwood amps are really bad amps when it comes to ground noise.  I had an MTX amp that I replaced with a Kenwood and as soon as I put the KW in, I had engine noise.  I put in another KW amp, and still had engine noise.  I put the MTX back in and like magic the engine noise is gone.  Also, I used to install at Best Buy (we sold KW there) and we had a big rig we hooked up a KW to--and sure enough engine noise.  Put in another KW--engine noise.  Put in a Rockford Fosgate and like magic the engine noise goes away.  If you bought the amp somewhere where you can return it, do so and get yourself something more reliable (rockford, mtx. kicker, alpine, infinity, eclipse)

Uhhhh, a couple of points here. First this amp has speaker level inputs so an LOC is not needed. Second if you used signal sensing trigger like a PAC TR-4 you would not need a remote or ignition lead. Last it is highly doubtful you would hear engine whine on a subwoofer amp. The job is easy, give it a try.There is no such thing as free installation!