The most difficult part of this achievement is finding the Olives resource on the map. You can set the Resources at the beginning of the game to "Abundant" to add a higher chance of seeing said resource. Note that they'll only spawn on grassland, so having an arid map-type won't help.
When you've found an Olives resource, settle a city near it and have a Builder farm it (this requires the Irrigation technology). Then simply declare war on an enemy, wait the required amount of turns before you can make peace (usually 9 turns) and then when making peace, offer your Olives resource in the deal. More often than not, the AI will agree to the deal and the achievement will unlock straight afterwards.