Go in to the audio place, and check out the Contour harness's, at some spot near you, support your local sales, but maybe not the labor costs lol, im j/k.
Swoop up those harness's for HU, and the amp bypass one.
Next, prepare for purchase online, or at the store or whatnot for the deck. I recommend a new deck ebay sale from a reputable seller.
heres one for bypassing the amp,
gather the contour harness and bypass harness,
the HU harness connection is simple, follow thru with the amp bypass and you should be good.
You own your car, why not get to know it a lil better, but I do see that HU sales these days include a free install and blah blah blah.....but its really simple to install a HU. Everybody should do it at least once in thier life.
Take your new deck, with your new contour harness, and in the comfort of your kitchen or living room, attach the new harness to the HU, (dont sweat outside) make good firm grabs on those connections, solder, crimp, whatever.... Then go outside and plug it in, run the amp bypass and enjoy.
The removal of the stock deck can be frustrating, but be patient, and line up those U Forks and pull. Maybe someone can describe a tug or wiggle or somethin, but just get that darn thing out lol.