As you are walking the New Vegas Strip, an NCR trooper will approach you and give you a message, which asks you to visit Ambassador Dennis Crocker at the NCR Embassy. The embassy is in the last section of the Strip (farthest from the North Gate). Crocker is in the building on the left once you enter the front gate. Once inside, go through the door on your left to the end of the hall to find Crocker.
This quest disregards your reputation with NCR; even if you are Vilified with them, you still are allowed to enter the embassy and talk to Crocker.
The wording on "getting rid of bad reputation" can be misinterpreted. That being, if you have a mixed neutral or above, your reputation will remain unchanged. Only if you have below neutral reputation will it change.
Already being Idolized by the Boomers allows the player to bypass this quest.
xbox360 After telling Crocker you've gained the Boomers' support, an NCR MP will stop you in the hallway, say something about how you "should have paid your dues" and become hostile. He and any other NCR troops in the hallway will attack you, but killing them doesn't result in karma or reputation loss, and no other NCR troopers become hostile afterwards. [verified]
pc When you ask Pearl to aid you in the upcoming battle, there will be no dialogue options except "goodbye". [verification overdue]