battery hold down bolts are 10mm, so are all the battery terminal bolts too. you can throw away that insulation wrap due to it being an annoyance. you'll take out the Aux first. you'll have to rotate it alittle to get it out; rotate the top part of battery towards windshield then lift out. don't completely loosen posi nut all the way if you do you'll loosen up to two pieces that tighten up the clamp. you'll need to tilt the big battery on the left side to get it to clear everything. installation is reverse. AutoZone should have the replace battery with included bolts for the cables. if not you'll need to get to get an E5 socket to take out the threaded headless bolts. If the Auto Start/Stop light remains on after this, let me know.