You can either just get this through normal play any maps. Try to always be the person getting into bases and hacking them. Otherwise, here's how to set up games to get this.
Set up an Offline game on any map you like, I would use the new maps just for variety. Make sure to hit X in map selection so you can play on the large
version (thus more points to capture), and set bots to Trivial. Leave the
player amount as 16 (you'll see why in a second).
Start up the game. It's random in Assault whether you start as attackers or
defenders. If you do start as defenders, quickly switch to the other team by
pressing Y before spawning, then selecting the other team.
As always, use a good assault class with a Jammer beacon. Drop in and start attacking and hacking CPs. You also need to capture it, so defend them to the best of your abilities. Once you've captured one, move on to another.
A few notes. Your teammates may capture CPs as you're busy at another one, this doesn't count for this achievement but you can't really stop it so don't worry. If possible, let the enemies defuse it, then hack it yourself.
Once your team has 3 of the CPs, the enemy team goes into sudden death - after you kill an enemy one more time, he can't respawn for this round anymore. This is why you left it as a 16 player game, otherwise you'd quickly wipe out the team and this ends the round immediately. According to the patch notes for the June 1st title update, if you win by killing all the defenders, you still get credit for capture a CP. I would assume this only counts if you were in the process of capturing a CP and the round ends.
Once the round is over, quit out of the game and simply start a new one, repeating the steps above.