Simply go to a pub, the one in Bowerstone Market is probably the best to visit, and buy at least 5 alcoholic drinks from the bartender.
Once you've acquired 5 or more alcoholic drinks (think beer, wine), find at least 5 people (use the "follow" expression on people who like you to make your own group of 5 people if your having trouble finding citizens hanging around).
To give a person a drink, focus onto them with the left trigger, as though you were going to perform an expression at them. Bring up the expression wheel using the Right Bumper, select the "Social" section then "Gift". Scroll down the list and select "Food", then gift the villager with an alcoholic beverage. Repeat this 4 more times on 4 other villagers in the 3 minute time frame - easily doable.
Also note that it only takes 1 drink per person for the purposes of this achievement. Credit for attached video goes to Reabo.