Wow, you actually bought the over priced factory 12V plug? I looked at it when I was adding one to mine, and could not believe what they were asking for it. I bought one from a local auto parts store for $5 or $10 (came with the rubber cover / plug).
Either way, you'll be grinding metal to install it. I used a Dremel with small die grinding bit. I also ran a heavy gauge wire direct from the battery, so I can plug my Slime compressor into it without the bike running. Normally it's used for the power to my tank bag, when I'm on a longer road trip.
BTW, I have to agree with Pappy. Noobs are consistently informed about using the search function, as that's what it's there for (Max must have been snoozing), and this topic has been discussed several times before. Nothing wrong with starting a fresh conversation on the topic, just that the attitudes are unnecessary. Also, which one of you is supposed to be a moderator?