- Remind Debtors
In order to complete it without spending gold you need to have the first passive ability from either the Fighters or the Mages Guild (Intimidating or Persuasive Will). Unlocking one of these passive skills makes you able to influence Outlaws without giving them gold.
In order to unlock Fighters/Mages Guild talents you need to complete their introduction quests in Vulkhel Guard. Introduction mission’s name for Fighters Guild is "Aicessar’s Invitation" while its equivalent in Mages Guild is "Curinure’s Invitation".
Once you have one of the guild passive abilities approach the quest objective Outlaws at the nearby dock. Different Outlaws have different options to persuade them. Find the ones that have conversation option to influence them with your Fighter/Mage Guild passive ability. Once you persuade one of them, you receive + 1 Remind Debtors accomplishment. Once you find and persuade 5 of them return to Malareth for mission completion.
Note: with the lattes game update you have the third option. This option makes them fight vs you for the money. This however might be only the case if you have completed the starting area first…