Single black is your ‘hot’.
Red & White is the series link between the coils, just insulate/tape the tip so it can’t short if you’re not splitting.
Bare & Green (fat, looks like it’s got heat shrink on it) is your ‘ground’.

The wiring diagram was created when the supplied pickups just had 2 wires, but now the kits are shipping with 4-wire humbuckers. Just match the above to the diagram and you should be fine.