I doesn't get any easier than this.
The big plug connects where the original rectifier did, and it looks like this unit mounts using either the original rectifier mounting or the original regulator mounting - hard to guess... whichever fits.
The three loose wires connect to the three wires that originally attached to the stock regulator, color to color. Tape over the connections if metal shows so it won't go zap someday.
Edit:
I should read the question before answering.