TO REPLACE THE PNP SWITCH YOU NEED TO TAKE THE BATTERY OUT, THE BATTERY TRAY,I ALWAYS REMOVE THE AIR CLEANER BUT YOU DO NOT HAVE TO. AFTER I REMOVE THE AIR CLEANER I REMOVE THE CONNECTER THAT IS ON TOP OF THE TRANSMISSON. TO DO THIS YOU NEED TO PUSH THE SAFETY TAB DOWN AND PULL THE SILVER LEVER UP AFTER YOU HAVE DONE THIS CUT THE TWO TIE RAPS ON THE WIRE BY THE CONNECTER. TAKE A SMALL SCREWDRIVER AND PUT IT ON THE BACK OF THE CONNECTER THEN TAKE A PAIR OF PLIERS AND PULL UP ON THE CONNECTER AT THE FRONT OR THE PART THAT ALL THE WIRES ARE COMING IN AT THE SAME TIME PUSH ON THE SCREWDRIVER AFTER THE CONNECTER CAME APART TAKE THE TWO BOLTS THAT HOLD THE CABLE DOWN TAKE THE CABLE OFF THE PNP TAKE THE CENTER NUT OFF THE PNP SWITCH AND THEN THE OTHER TWO BOLTS MARK THE PNP SO YOU CAME LINE THE NEW ONE UP THE TOOL IS ABOUT 20.00 AT VOLVO. MAKE SURE THAT YOU DO NOT HAVE BATTERY ACID ALL OVER THE PLACE IF YOU DO USE ALOT OF BATTERY CLEANER FIRST AND A LOT OF WD-40 IF YOUR CAR DOSE NOT START ADJUST THE SWITCH WHILE YOU MOVE IT HAVE SOMEONE TRY TO CRANK IN GOOD LUCK.