Alright, I'll try to help out here & describe it as simply as I can.
The harness that comes with your Pioneer should look like this:
... and the harness that comes with the Beatsonic BH-1 is like this:
The first thing is to make as many connections between those two harness as you can in the comfort of your home. These two harnesses will snap nicely into the back of the Pioneer & to the stock wiring harness that comes to the stock deck.
You can almost tell that there are wires between the two that happily match up. You'll want to have bullet connectors handy to connect from the Pioneer harness to the Beatsonic (don't hold me to it, I think I had 16 ga... 18+ might work too). I also had some butt connectors hand for when I needed them (definitely 18-22ga for those).
That should take care of most of the basics: battery, accessory, speakers (front will be on one of the BH-1 harnesses, rears on the other 6-pin harness).
Then pop off the plastic plate around the deck. It comes right out if you pry it towards you, but I caution to use interior trim tools. I have a set I bought for $15. ... and it doesn't hurt to drape a towel over the open cavity left by your vacant deck, just so you don't scratch up your pretty A/C controls, shifter, & whatnot.
Then, after removing the deck with just the four bolts, I just transferred the stock metal side brackets to the new deck, added the black plastic Beatsonic pieces to get the deck ready for reinstall, then I finished these wiring connections at the car:
• ground (I added the parking brake safety as well), grounded on handy screw right there in the right side of that deck cavity
• remote wire (I already had a JL amp in there, so it was direct connect)
• accessory splice to BU camera (Y-split was already there)
• reverse sensor wire
• microphone
• GPS sensor
• antenna adapter (the previously mentioned Metra adapter), obvious antenna plus, plus a blue wire that goes to the 'powered antenna' wire out of the deck.
I see that the Metra adapter is available at Bestbuy for maybe $13?
I hope I helped more than confused... and some of the info here is specific to my install & won't help you (depending on what else you might be installing), but I'm open to any questions you have!
- Donn