Instructions
Travel to Nosalida. It is in the Punto Orgulla region in the southwest corner of the map, northwest of Escalera. Go well-armed and supplied with as many Fire Bottles as your inventory can hold. You will need these to complete the Nosalida hideout mission. You will hear sounds of fighting as you approach Nosalida.
Approach the Mexican soldiers taking cover behind some rocks outside Nosalida's gate. A cut scene will play in which the commanding officer requests your help fighting the bandits occupying the hideout. Agree to help. The Nosalida hideout mission will begin. The objective is to use your Fire Bottles to burn down each building the bandits occupy while defending yourself from attack.
Burn down each building in Nosalida using your Fire Bottles. The buildings yet to be burned are indicated by yellow dot icons on the map and the gang members yet to be killed are indicated by red dot icons. The Mexican soldiers will attempt to hold off the bandits while you burn the buildings, but you will need to be ready to fight. Kill any gang members that approach or attack. You will be summoned by the commanding officer once every building is burnt.
Go see the commanding officer. He is in the same location outside Nosalida's gates. He will thank you for the help and give you some money. The Nosalida hideout mission will end. The game automatically awards you with the Henry Repeater for successful completion.