Those gifts can be found in any difficulty
They spawn randomly, so if you can't find them as shown, just restart to get the achievement quickly




San Martin Bank

In the bus, at the right of the bank







Border Crossing

You'll find the gift on Day 2







Buluc's Mansion

Easiest and quickest way to find it : Use the Boat Entrance
The gift should be near the first door of the safe room




Breakfast in Tijuana

The gift should be in the back yard, near the prison cells





I hope this will help
Enjoy !