Hi guys, I am installing new coax speakers(JL C2 400), subwoofer(8" micro sub), and amp(XD 500/3) in my 2012 CMS, non HK. How do I get to the connectors for the HU? Is there a easier way than pulling the whole speedo out?

Also, should I even worry about the 2X 6.5 mid/subs under the seats? Any help would be appreciated. Thanks.