I got a garage to fit mine mate, best to get an auto electrician to do them if youre even the slightest bit unsure. Not questioning your knowledge but there's that much wiring going on there's a lot to potentially go wrong. Plus the tapping will look decent when done professionally with proper terminal thingys.
Where did you get them from? As long as there's some instructions with or without a wiring diagram then a garage will be your best bet. It cost me £90, but imo it's worth it to know it was done properly.