Grecks is located behind the Old Mormon Fort; he will pay his debt after a simply asking (or threatening) him, or by punching him the face (through dialogue).
Santiago is in the ruined building opposite Mick & Ralph's; revealing that he has a bounty on his head, or punching him in the face through dialogue will force him to pay his debts. If Wang Dang Atomic Tango is active, he can alternatively be convinced to work off his debts.
Alternatively, he can be convinced to hand over his hat and debt money with a Speech check of 40.
Return to Francine.
Collect 138 caps from Grecks in Freeside.
Collect 212 caps from Santiago in Freeside.
Collect 250 caps from Lady Jane.
(Optional) Find Lady Jane's caravan and collect caps from the remains.
Kill Caleb McCaffery.
Return to Francine with McCaffery's hat.
PlayStation 3PCXbox 360 If the quest Wang Dang Atomic Tango has already been completed and Santiago was hired as the suave talker, there is a possible bug that you will not be able to talk to Santiago to collect the caps. It is still possible to complete the quest by pickpocketing the bag of bottle caps off of him.
PCPlayStation 3 If choosing to obtain Caleb McCaffrey's hat peacefully through a speech check, putting on his hat afterwards causes the game to freeze.
PCXbox 360 If Caleb McCaffrey is the first bounty you get and complete by passing a speech check, returning to Francine Garret will complete the mission without having to find Grecks and Lady Jane. If you go after Caleb McCaffery before Lady Jane, you complete the quest. However, his room does not become yours, despite Francine awarding it to you, all items in it are still 'owned' by someone else and you cannot sleep in the bed.
PCXbox 360 It's possible to turn in the quest with Francine before it's finished and thereby adding Caleb McCaffrey to the existing quest line but at the same time making it impossible to talk to Lady Jane.
PlayStation 3Xbox 360 Upon completing this quest and killing McCaffery, any attempts on re-entering the Strip will result in a black screen crash and the autosave corrupting (some users have reported The Strip door also requiring a key).
To fix the black screen crash, wear the Old cowboy hat (or even Caleb McCaffery's hat) that you can find at Blake's shop in the Crimson Caravan Company (it's near a bunch of first aid boxes). Wearing it before entering The Strip from Freeside will stop the game from crashing. The key-requirement for The Strip gate can easily be solved by taking the NCR monorail in Camp McCarran to the Strip, and then opening the gate from the inside. If you cannot use the monorail, stealthily kill one of the Securitron guards near the gate and loot the key from its corpse.
To avoid the black screen crash, try not to decapitate Caleb; if McCaffery's body is intact when you remove the hat and other items from it, the visual of the hat disappears from the corpse. It is unclear why this was occurring but when his head separated from the rest of the corpse, the image of the hat on McCaffery's head remained even when his corpse was looted, causing the bug above.
PlayStation 3Xbox 360 Following closure of the dialogue when asked to kill McCaffery, he may be involved in a firefight inside the Atomic Wrangler. He will appear friendly in V.A.T.S. and be fighting with Wrangler staff. You can kill him here and get the reward before entering the Strip.
PlayStation 3 The player may be unable to ever open dialogue with Lady Jane (attempting to simply triggered a passive statement about ED-E). Repeated attempts caused her to repeat the statement. This can be very problematic and render the quest unable to be completed without killing or pickpocketing her.
Xbox 360 In some cases, if you kill Caleb McCaffrey before you start this quest, you will not be able to complete it or if you pick up McCaffrey's hat, you won't be able to drop it, as it will still be marked as a quest item.
Xbox 360 When asked to kill McCaffery, there's a possible bug where you will be unable to select any dialogue options. (Pressing start when this happens will fix it).