Getting a Leg Up from Andy

Getting a Leg Up from Andy is an unmarked quest in Fallout New Vegas

Detailed Walkthrough
Former NCR Ranger Andy, who is currently residing in Novac will ask the courier to check on Ranger Station Charlie. Upon arrival at Ranger Station Charlie, you will find that all the rangers have been killed, leaving behind 2 holotapes, the first one located under the desk, and the second one right next to the desk. One major statement is that they captured a female Ranger (possibly the female Ranger you have the option to fight in the arena at The Fort). They detail that Caesar's Legion is sending a message to the NCR. Return to Andy and he will give you 200 caps, plus an increase in reputation for both the NCR and Novac. There is also a speech check you can complete for 60 speech, which will net less reputation with NCR and Novac but 200 more caps.

By completion of this unmarked quest, Andy will give you a perk called Ranger Takedown and teach you how to do the Ranger Takedown. Alternatively,you can pass a level 30 speech check and he will teach you the move.