Final question:
Do I break my lifetime-warranty when I remove that black insulation cover?
No, I'm sure you don't - the insulation's only there to stop the pickup shorting out if the green/white wires come into contact with other wires or metal parts.
Here's an HSH wiring diagram that will split the coils of the humbuckers in positions 2 and 4 on the switch:
http://www.dimarzio.com/media/diagrams/C.pdfIt's a DiMarzio diagram, so you need to convert to BKP colour coding:
DiMarzio: Red, White+Black, Green
BKP: Red, White+Green, Black