This activity can be acquired from a farmhand who works in the allotments south of the monastery and north east of the Sasau Wagoners' Inn. He has a grievance with the local herbalist, and wants you to steal an amulet from him. The herbalist is labelled as a villager, and can be found patrolling around the allotments. You can steal the amulet either by pickpocketing the herbalist, or knocking him out first and then looting the body. When you have the pouch with the amulet inside, take it to the farmhand.
The next task the farmhand has for you is to steal the shawl of a woman he would like to court. Unfortunately for him she is already courting someone, but he has a plan for what to do with the shawl which might change that. The location of the woman is marked on the map. Go to her and either pickpocket or knock her out to acquire the shawl.
The last task of the activity is to steal a tinderbox from the Sasau tailor. This one is more difficult to accomplish during the day, due to him being accompanied by at least one person at all times. You should therefore wait until after midnight and knock the tailor out while he sleeps. You can then loot the tinderbox from his body.
You will find the tailor in his bedroom. Go up the stairs from the workshop and turn left. You will find a guard sleeping beside a locked door. It is a good idea to knock the guard out before you proceed. Pick the lock of the door to enter the room where the tailor is sleeping. You can now pickpocket him and steal the tinderbox.
If you have got this far in the quest, you are probably wanted by the Sasau guards for all of the terrible deeds you have done. It would be wise to leave the town and wait a few days for their investigations to go cold before turning to the farmhand with the tinderbox.
After a few days the red jail icon appending the Sasau name on the map should have disappeared. You can then go back to the farmhand to complete the activity.