For this achievement, you first must select the correct tournament, go to club tournament and cycle through the trophies. When you find the tournament named "World Trophy", it should have Offline Cup written above it.
After finding the tournament, you now must win it. These Offline tournaments are against the CPU, so if you want a stroll in the park, set the CPU difficulty to Amateur, but be warned you will receive only 500 coins per match with a 9-0 win.
Each trophy has three stages, bronze, silver and gold. Before you can tackle the gold tournament you must win the bronze and silver. To win a tournament you must win 4 matches. For example, win four matches in a row and you will have the bronze trophy, win another four you will have silver, and finally win four more and you will have gold trophy.