Very easy and you'll likely unlock this through natural gameplay. To attract a caragor with bait you simply have to shoot the hanging meat (often found in and around strongholds) which will draw caragors into the area to wreak havoc on unsuspecting uruks.
Quick tips:
If you're having trouble finding the bait to shoot you can use your "wraith vision" (default is
) and it will highlight the bait along with other things like uruks and Morgai Fly nests.
You probably won't need to shoot five separate bait, but rather attract a total of five caragors with bait. For example, I had only shot/activated two or three separate bait when the achievement unlocked for me.